POPULATION STUDIES

                                         

          TOPIC 1: GLOBAL POPULATION DYNAMICS AND DISTIBUTION

Definition of terms

Human population refers to the number of people in a given geographical unit areas.

Population dynamics- Refers to the changes in population size and structure brought about by mortality, fertility and migration; It is a change of population in relation to time and space.  It is a change in growth rates, change in distribution; density, sex ratio and ages structure.

 Population distribution means the pattern of where people live. Distribution tends to change according to time and place. 

Density- Refers to number of people per unit area of land.

Sex ratio: Relationship between number of male and female.

Growth rate: The number of persons added to (or subtracted from) a population in a year due to natural increase and net migration; expressed as a percentage of the population at the beginning of the time period.  

Age structure: Composition of population in ages e.g. 0-4, 9-15 children; 15-60 working groups, 60yrs old. i.e. composed different Age groups.

WHY IMPORTANT TO UNDERSTAND POPULATION DYNAMICS?

In order to understand labour requirements in society and other requirements like food, health facilities education services etc.

It helps in population projection to know how many people will be born at a certain period of time.

Generally people will like to know their number and rate of increase because distribution of resources and social services depends on their number.

                                           GLOBAL POPULATION DYNAMICS

Before industrialization global population has been growing very slowly, but beginning the industrial revolution more particularly in 1950s global population started to increase very rapidly.

The world population in 1 AD was 300 mil people, increased up to 800 mil people in 1750 with growth rate of 0.1% per year. In 1920 the world population was about 1.8% billion people,  it continued to increase in mid 1950s the world population was about 2.5 billion people,  it increased to about 4.4 people in 1980;In 1990 it was about 5.3 billion people in 2001 it was about 6.1 billion people.  In 2011 it reached 7 billion and is estimated that by the year 2050 the world population will be 9.3 billion.

Table 1 World Population Growth

1AD	300 million
1750	200 million
1920	1.8 billion
1950	2.5 billion
1980	4.4 billion
1990	5.3 billion
2001	6.1 billion
2011	7 billion

Figure 1: History of Human Population

World Population Growth, 1750–2150

Source: United Nations, World Population Prospects, the 1998 Revision; and estimates by the Population Reference Bureau.

This data indicates that population is dynamics in terms of time.

Why there is rapid population growth after Industrialization? Because of economic development which after industrial revolution, This economic development made possible to have better technology which led to increase in food production; improved medical and sanitation and other social services.

These factors tended to raise fertility rates and lower mortality it should be noted that both mortality and fertility rates are decreasing but mortality decreases faster than fertility.

                                  GLOBAL POPULATION DISTRIBUTION

Population distribution means the pattern of where people live. World population distribution is uneven. Places which are sparsely populated contain few people. Places which are densely populated contain many people. Sparsely populated places tend to be difficult places to live. These are usually places with hostile environments e.g. Antarctica. Places which are densely populated are habitable environments e.g. Europe.

Generally there is spatial global variation in population distribution and these variations are identified in 3 characteristics.

1.         Size of Population: Less developed countries have about 79.8% of the world population of which China takes 20.8% followed by India of 16.7% and the rest of the world is 41.3%.

            DC’s contribute 20.2% of the global population with about 1 billion while the population of the developing countries is about 5 billion.

2.         Growth rate; Global average growth rate is 1.3 per year however it varies between countries, developing countries have average growth rate of 2.1 and Developed countries have 0.6.

3.         Population structures of LDC’s have high proportion of children while in DC’s have high proportion of old people.

                             Factors Affecting Population Distribution

There are a range of human and natural factors that affect population density. The tables below illustrate this.

Physical Factors	High Density	Low Density
Relief (shape and height of land)	Low land which is flat e.g. Ganges Valley in India	High land that is mountainous e.g. Himalayas
Resources	Areas rich in resources (e.g. coal, oil, wood, fishing etc.) tend to be densely populated e.g. Western Europe	Areas with few resources tend to be sparsely populated e.g. The Sahel
Climate	Areas with temperate climates tend to be densely populated as there is enough rain and heat to grow crops e.g. UK	Areas with extreme climates of hot and cold tend to be sparsely populated e.g. the Sahara Desert
Human Factors
Political	Countries with stable governments tend to have a high population density e.g. Singapore	Unstable countries tend to have lower population densities as people emigrate e.g. Afghanistan.
Social	Groups of people want to live close to each other for security e.g. USA	Other groups of people prefer to be isolated e.g. Scandinavians
Economic	Good job opportunities encourage high population densities, particularly in large cities in MEDCs and LEDCs around the world.	Limited job opportunities cause some areas to be sparsely populated e.g. Amazon Rainforest

                   POPULATION DYNAMICS AND DENSITY IN AFRICA

Population estimation for Africa was 141 million in 1920 which represented 8% of the world population; the population increased to about 470 million people in 1980 to about 818 in 2001.

Year	Number of People in
	000,000
1920	141
1980	470
1998	780
2001	818
2007	965

This trend shows that population growth in Africa has been changing from time to time

and the share of Africa in the world population has been increasing over years from 8%

to 13% by the year 2001.

With in Africa there are variation in population growth and size between regions;

By 1997 and 2001 Eastern Africa had the largest population in the continent followed by

Western Africa and middle Africa; South Africa has the smallest population proportion

than all other regions.

The population estimate by the year 2010 indicates that western Africa take the lead in terms of population size, this is be due to variation in growth rate between one region and another.

DISTRIBUTION OF POPULATION IN AFRICA BY REGION IN 1997 – 2001

REGION	1997	2001	GR IN 1997
West Africa	210 million	240 million	2.9%
East Africa	231 million	252 million	2.8%
Middle Africa	88 million	99 million	3.1%
South Africa	49 million	50 million	1.7%

POPULATION DYNAMICS AND DENSITY IN TANZANIA

Year	Number of People in
	000,000
1948	7.4
1957	8.6
1967	12.2
1978	17.5
1988	23.1
2002	34.6

Source URT (2002)

                                      END OF TOPIC 1

                   TOPIC 2: POPULATION DATA, STRUCTURE AND THEORIES

Population Structure - Developing Countries

This population pyramid is wide at the base, which means there are a large proportion of young people in the country. It tapers very quickly as you go up into the older age groups, and is narrow at the top. This shows that a very small proportion of people are elderly.
This shape of pyramid is typical of a developing country, such as Kenya or Vietnam.

Population Structure - Developed Countries

This shape is typical of a developed country. It is narrow at the base, wider in the middle, and stays quite wide until the very top, as there is a sizable percentage of older people. Note that there are more old women than men. Italy and Japan have population structures that are of this

 SOURCES OF POPULATION DATA

Basically there are 3 main sources of population d

(i)                  Census

(ii)                Vital registration

(iii)               Sample survey

Census

Most Less developed countries like Tanzania depend on census in obtaining population data.

Census refers to a total process of

 collecting, compiling and publishing demographic, economic and social data pertaining to specified time(s) to all people (persons) in the country. A census therefore, is population profile where by the main social

Types of census

(i)                  A dejure census

(ii)                A defacto census

A DEJURE CENSUS

Is a type of census in which the people are counted according to their usual place of residence. Only permanent members of household are counted.

A DEFACTO CENSUS

Is a type of census in which people are counted wherever they are found on the day of enumeration (enquiry) ask people who stayed in the household for the night are counted.E.g Tanzania

OBJECTIVES OF CENSUS

1.      To obtain count of all members of a country by age and sex, this is important for planning as it helps on estimating both, death and growth rates;

      2.   To obtain detailed statistics on size, nature and distribution of the labour force.

     3.    To determine the literacy and illiteracy rates of the population, census helps to provide information on the distributions of literate population on different educational and technical levels and helps to know the scientific capacity of the population /society.

     4.    To provide socio – economic information on household and housing conditions such as occupancy, type of ownership and availability of household facilities.

     5.    To provide a complete picture of all places and persons, villages, wards and

Households for the whole country, such picture is useful for planning development projects.

   MERITS OF CENSUS

Census doesn’t suffer from sampling errors it covers the whole population in a country or region and every individual is enumerated.

The results of census can be easily compared with the result or other countries because of its Universalities features.

Since census is taken at a regular interval, it is the most popular source of demographic data.

                                      FEATURES OF A CENSUS

The United Nations (UN) suggests the following as the essential features of a census.

1.                  Individual enumeration

   When a census is carried out it requires that every individual is listed with her/his personal characteristics separately; It is only in rare cases where enumeration can be done to cover the community.

  2.       Universality within defined Territory:

           For census to be valid it must cover the whole country including the absent or those who are traveling in buses, trains complanes etc, if the condition is not fulfilled by whatever reason e.g. war isolated tribes it is important to indicate the proportion of population which is not covered.

3.         Simultaneity –

           To have any comparative logic census have to be taken at fixed date and time, it must relate to a single point in time and not a period even though the enumeration itself may be spread over days/weeks for example in Tanzania census which was conducted in 1948, 1958, 1967, 1978, 1988, 2002 it was taken on the last Sunday of August.

4.         Defined periodicity;

          It must have a legal basis thus making it compulsory for every person to be included and provide information requested, it can not be involuntary exercise.

        DEMERITS OF CENSUS

·        Census is often postponed due to lack of money e.g. in Tanzania 1978 to 1998 census was postponed due to lack of money.

·        Census are expensive exclusive in Texans of time needed to compile and processing data to this make census to be carried out on Interval of about 5 – 10 years.

·        Census processing required too long period of time and sometimes they can’t satisfy agent data requirements.

·        It is too difficult to collect detailed information in census because it covers the whole population.

ERRORS IN CENSUS TAKING

Errors in census taking are very great especially in under developed countries, the

Errors fall into 2 groups.

(i)                  Incomplete coverage (over countries)

(ii)                Response errors/quality of answers

(i)         INCOMPLETE COVERAGE

Under count may arise because the whole area or sol groups are missing e.g. homeless infants, students, vagrants, seamen, street children, and those who are living in institutions.

(ii)        QUALITY OF ANSWERS

This may arise accidentally or due to enumerators recording the answers wrongly.

·        The respondents misunderstand the questions

·        The respondents not knowing the answer if the question being asked is in- appropriate to cultural aspects.

·        Sometimes responses errors may be deliberate e.g. for the reason of pride, shame of fear, for example unmarried person may decide to omit to mention her children;

·        The household may overstate the size of the house hold or divorces people may declare themselves as single.

                                          SAMPLE SURVEY

This involves collecting population data from a sample population, the sample must be taken in such a way that it can explain/describe as accurately as possible some demographic aspects of the population.

·        The demographic aspects are fertility, mortality and migration together with main factor which influence them.

·        Sample survey refers to small proportion of the population to information collected to represent the whole population.

TYPES OF SAMPLE SURVEY

(i)                  Simple round survey

(ii)                Mult-round survey

SIMPLE ROUND SURVEY

Normally involves only one interviewer with the respondents the type of survey is more convenient in the country whose the population is more mobile.

MULT – ROUND SURVEY

Mult – round survey includes varieties of designs.

(i)                  Surveys which interviewer the respondent several times.

(ii)                The survey which interview similar respondent so that they can produce the indication of the trends over time; e.g. the Tanzanian household survey; labour force survey etc.

Advantages of sample survey

1.                  Sample survey is simple to carry out and administer

2.                  Sample survey is more flexible than census

3.                  It has relative low cost.

4.                  More detailed information to another.

                                       Disadvantages of sample survey

1.                  Sample survey faces the problem of sampling errors e.g. business

2.                  Not easy to compare information to another.

                                              Vital registration

A vital event can be defined as a major change in individual status which can lead to change in population.

·        Vital registration includes registration of death, birth, migration, marriage, adaptation, legitimization, separation, divorce, and Annulment.

·        The method is not very well used in most developing countries because it requires very developed records to reporting system.  In Tanzania some experiments were conducted in Kilimanjaro and Morogoro regions to encourage collecting some vital events but unfortunately the project was not funded of completely collapsed.

                                               Population structure

Population structure is the population of males and females in each age categories; population structure is determined by the number of proportion of males and females in each age category.

The Age structure of a population can be presented graphically by a population pyramid. Population pyramid is either drawn in percentage which shows the composition of each age and sex with the total population or may be drawn by using absolute number

 

 

 

                       

The age sex structure of a population is a cumulative result of the fertility, mortality and migration. Usually to demonstrate how these factors control population dynamics typically the population with high to rapid birth rates have a young population particularly those less than 15 yrs this is more common in developing countries as a result the population pyramid drawn is broad based.

The population which has a slow growth rate/stationary population has small number of children than adult and old people this is very common features in developed countries such as west Europe, North America and Japan

                                              Why study age structure­

·        It is important to learn about age and sex population structure because several demographic event which determines population dynamics such as birth, death and migration are strongly related to age structure:

·        These factors (birth, death and migration) are normally age selective e.g. Biologically birth occur to mature women more often aged 15-49yrs when birth occur below or above these ages they are usually accompanied by risks although among males the virility has no age limit; it begins after puberty which in most societies starts at the age of 14-15yrs.

Mortality is more concentrated in age less than 5yrs specifically in the age under 1 yrs

Migration the age group which are more prone to migration are those working group (15-64yrs)

Education circles

Has a tendency of following age structure e.g. in Tanzania Kindergarten (Nursery) involve children of 5-6yrs, primary (7-13yrs), secondary 14-20yrs) and Tertiary 20 and above; However it is important to note that this age structure in education is only followed if there is not restriction and at entry is strictly followed.

Labour force

Effective labour participation starts at 15yrs-64yrs.

                         Measures/indices of age structure

1.         Dependency ratio (DR)

DR is a ratio which shows the relationship between the population which involves in production (Active labour force) and those who are economically inactive; normally DR measures the division of labour within the population.

                 Mathematically;

                                           DR =        Pop – 14 + Elders (65 +) x 100

           

                                                   Pop 15 – cost 64 yrs.

DR =   Children under 14yrs + Elders (65 +) x 100

 

Working population 15 – 64 yrs.

If the answers is above 50% it means that the population has high dependency ratio; for instance the census of 1988 data for Tanzania indicated that 10,529, 939 were children under 14yrs and 981, 839 were Elders above 65yrs  similarly 11; 546, 450 people were in the economically active age group (15-64yrs) calculate the DR.

DR =   10,529,939 +981,839 x 100

           

            11,546,450

DR =   11,511,778 x 100

 

            11,546,450

                            DR = 99.7%

The interpretation of this DR is that for every 100 working population, there are 99.7 dependants so one worker works for almost two people.

2.         Sex ratio (SR)

Is a ratio within a population of a total number of males over the total number of females in the population

I.e.       SR =    Males of Age

                                                 X 100                                      

                        Females of Age

The most quoted SR is the SR at birth which has been scientifically proved that to every 100 females there are about 105 males born; But it does vary between population and subgroups; However these advantages of having more males at birth has not maintained at long parcel because of differences in mortality and migration; in most parts of the world female mortality is lower than male in all groups the women live longer than men.

In migration many large scale migration streams contain a low sex ration of these ages in the area of origin and high ratio in the area of destination.

Example 1988 census in Tanzania 0-4 males (19,222,487) female (1,951,231)

SR =    19,222,487 x 100

 

            1,951,669

=          98.5%

40-44 yrs: Males = 3,680 441; Females 421.669

SR =    3,680,441   x 100

 

            421.669

            SR = 87.3%

Indicates that Males are fewer than females

Population pyramids

Population pyramid is double bar sharing the same ages sexes structures of the population and usually it consists of 2 sets of horizontal bar graph one for each sex;

Population pyramids are elegant and useful way or graphically presenting an age sex distribution.

Principles/rules for drawing population pyramids

1.         Piramids are always drawn showing the males population on the left hand side and females population can the right hand side.

Also young are always put at the bottom and the old at the top;

It is also a principle to use either single one year or 5yrs age group

Diagram

2.         The last age group is normally open ended because some people might survive

            over 100 years and it is impossible to draw truthfully.

3.         The bottom scale can be graduated either by absolute numbers or percentages.

·        If the population pyramids are drawn by using percentages they should be calculated by using total population of both sexes.

·        If the percentages are calculated separately for males and females then the pyramid will present a false picture.

4.         The choice of scales affect greatly the final shape of pyramid e.g. stretching of           the age and squashing the horizontal one will produce a tall thin pyramid.

           

POPULATION PYRAMID   

Diagram

(a)               The shape of the Graph is bottom broad which implies that these is high rate of fertility rate because the number of Young.  People 0-14yrs are high and this is LDCs oriented type of Age structure.

(b)               SR =          Number of Males  x 100

 

Number of Females

SR =             10776 x 100

 

                     11717

SR = 91.96% Indicates that females are many than males     

(c)               DR =         Population >14yr + 65 + yrs  x 100

 

Population 15 – 64yrs

            DR =               10543  x 100

 

                                    11950

            DR =               88.2%

The population has greater Dependency Ration as DR is greater than 50%

DETERMINANTS OF POPULATION STRUCTURE AND SEX RATIO

Age sex population structure is determined by 3 variables whether fertility, mortality and migration.

·        In most occasion fertility is the most determinant of the young age group specifically mover of any population structure it is followed by mortality which gradually ended or reduce the population.

·        Mortality affects almost all age groups; migrations influence the working Age group: International Migration may affect the population of the country internal migration affect the age structure of some region of the country not of the total country i.e. migration within the country cannot affect the structure of population of the country.

Diagram

MEASURES OF POPULATION

FERTILITY – In demography fertility refers to child having performance of individuals, couples, groups of population.  More often is contradicted by fecundity shows the capacity to reproduce which may or may not lead to fertility.

·        Bongarts and Porter (1993) estimated that the maximum number of children an average a woman can produce is 15.3 children if she starts child bearing as soon as possible after menarche which occurs in the ages 12-14yrs and continues.

·        In general there is no population which reaches the biological maximum and there are not of variations.

Determinants of fertility

Basically the determinants which influences fertility are classified into 2 main groups

(i)                  Proximate determinants

(ii)                Socio-economic and environmental factors (Background variables)

Background Variables

Includes the socio-cultural, Economical, Institutional, Psychological, Healthy and Environmental variables.

Proximate determinants

These consist of all biological and Behavioural factors through which the background variable must operate to affect fertility. 

·        The principle xstics of a proximate determinant it has direct influences on fertility which socio-economic variables can affect fertility only indirectly by modifying the proximate determinant; proximate determinants includes the following.

1.         Proportion of women married in sexual union (sexual relation) the variable measures the degree to which women of reproductive age are exposes to risk of                     conceiving; this variable also depends on;

(i)                  Age at its marriage

(ii)                Frequency of divorce, widowhood, re-marriage and whether the marriage was romantic or forced marriage, type of marriage polygamy or monogamy.

2.         The frequency of intercourse, this directly affect the probability of conceiving

among ovulating women, frequent or prolonged spousal separation has sub stantial  fertility reducing effects.

3.         Post partum abstinence; prolonged abstinence from sexual relation while a new

born is breast feeding is common in many societies this also reduce fertility.

4.         Lactitational Amenorrhea following a pregnancy a woman remain unable to

conceive until the normal patterns of ovulation and menstruation is restored (depend on the intensity of breast feeding).

5.         Contraception, Any practice undertaken deliberately to reduce the risk of

            conception is considered as contraception if it aims at limiting the family size.

6.         Induced Abortion, this includes any practice that deliberately interrupts the

normal cause of gestation;

7.         Spontaneous inter-uterine mortality, some pregnancies spontaneously terminate pre-matured in mis-carriage or still birth

8.         Natural sterility; sterility refers to inability of woman to conceive this may be

before menarche of after monarchy until menopause; this increases with age and reaches 100% at the age of 50s.

9.         Pathological (diseases) sterility; A number of diseases especially gonorrhea       can cause primary or secondary sterility; because the disease is contracted before birth and secondary sterility results into inability to bear an additional children.

Meas ures of fertility

 Introduction:

Fertility can be analyzed by 2 ways period fertility and cohort fertility.

·        Period fertility measures loops of fertility cross-sectionally i.e. it looks at births occurring during specific period of time on the other hand cohort analysis looks fertility longitudinally which it looks at births occurring to a specific group of women normally those married in a particular year.

·        In this case cohort analysis it looks in birth during reproductive history of women.

Period fertility

Is normally measured by Rates and Ratios which are captured from child birth; the calculation of Rates and Ratio depends on data available some of major Rates and Rations are;

(i)         Child-women Ratios, this is ratio which is computed from the number of children

aged 0-4 divided by number of women in child bearing age.               

CWR =            Children Aged 0-4                                         x1000

 

                        Number of women in bearing age 15-49

Is commonly expressed for 1000.

e.g.      Total number of children 0-4 = 3.873.718

            women aged 15-49 = 5.298.844

CWR   =          3.873.718 x 1000           

 

                        5.298.844                  

CWR =            730; i.e for every 1000 women there is an average of 730 children; this measure is rarely used simply because it is very crude because it includes even the women who are not in risk of getting birth,

·        However Children – women Ratio (CWR) is very high when fertility level is also high and if fertility is low then the Ratio will be low; the method can provide distorting inform especially when these is misreporting errors of birth and high level of infant mortality those fore it is dangerous to use this ratio to compare population with different levels of infant and child mortality and high level of misreporting births.

(ii)        CRUDE BIRTH RATES (CBR)

This is a ratio of life births in a specific period of time and usually one year to average population of that particular year; the ratio is also expressed per 1000.

CBR = Life births per year                                        x 1000

           

Total population (mid year population)

E.g. In 1967 census report of URT total number of births was 646,474 total number of mid year population was 11,957,933

CBR =             646.474          x 1000

 

                        11.957.933

CBR = 54

It shows that for easy 1000 people those ways 54 children; This measure refers crude rates because is includes both sexes and ages in the year instead of considering only women who are at a risk of giving birth i.e. it is not a good measure of fertility; normally CBR 10 per 1000 people to DCs and 50 per 1000 in LDCs due to poverty in those LDCs.

(iii)             GENERAL FERTILITY RATE (GFR)

This is a population of children from alive per 1000 women in her reproductive period in a year.

GFR=              Total birth in a year                           x 1000

            Mid yea population of women aged 14 – 49

It commonly given value per 1000 i.e. in each 1000 women these are certain number of children from census data of Tanzania mainland, Total Birth =635, 490, number of women/female aged 15 – 49 = 2.737, 646.

GFR=   635.490   x 1000

            2.737.646

GFR= 232.1 per thousand women in each 1000 women that is 232.1 children.

Through it considered only women who on risk of giving birth still it is not a good measure because not all women aged 15 – 49 must give birth; therefore it may mislead.

(iv)  GENERAL MARITUAL FERTILITY RATE (GMFT)

Is the ratio of life births in marriage + married women aged 15 – 49 per 1000.

GMFR=          Birth of married women         x 1000

                        Married women Aged  14 – 49

So it is important to note that General marital fertility rates may suffer in the population where martial birth is high; the range of General Fertility rates + general martial fertility rated is from 50 -300 in developing countries

(v)   AGE SPECIFIC FERTILITY RATE (ASFR)

This is the number of life births accruing to women of a particular Age group per year and it is normally expressed per 1000 women.

ASFR=            Total births in Age group (x)             x 1000

            Total females population Aged group (x)

Age sex fertility in Tanzania mainland in 1967

Age Group	Women	Birth	ASFR	Percentage
15 – 19	544533	91.836	168.7	11.6
20 – 24	513998	171.464	334.4	23.0
25 – 29	543729	171.874	316.1	21.7
30 – 34	378012	98.152	259.7	17.9
35 – 39	317864	63.815	200.8	13.8
40 – 44	219540	25.815	114.9	7.9
45 – 49	219970	13176	59.9	4.1
TOTAL	27733646	635490	1454.3	100%

The data from the table can be presented graphically as follows:-

The table in the graph shows that there is low contribution in the younger age which is 15-19 because this young age women are not married and some of them are no mature enough to give birth; also the older age group contributes less to fertility because they are too old to give birth i.e. 45 – 49 for a long time the peak of birth lies in age group of 20 -24 followed by the age of 25 -29, this indicates that on the age above 20 the women are physiologically mature to give birth and healthy wise the younger and old aged are extremely at risk to give birth.

(vi)   TOTAL FERTILITY RATE (TFR)

This is the sum of the ages specific fertility rate over a range of reproductive ages for a particular period it can be later preferred as the number of children the women will have during life time if she was to experience the fertility rate of a period at each age;

This is among the fertility measure which are widely cited and some how uses the concepts of Hypothetical cohort  in order to get overall summary of the fertility level an affected bay age structure

TFR= 5.Σ ASFR

From the table above total fertility rate (TFR) can be calculated as follows:

            TFR= 5. Σ ASFR

                             1000

            TFR=    1454.3   x 5

                             1000

TFR=     7270.5

                             1000

            TFR = 7.3 per women

(vii)           GROSS REPRODUCTIVE RATE (GRR)

This is the measure which indicated the average number of daughter that would be born to a woman during her life time if she pass through the child bearing ages experiences the age specific fertility pattern of a given period; as the total fertility rate in this measure uses the notion of hypothetical cohort although it may be used into 2 cohorts since only females are used in the calculation of this measure it is related to the TFR in the following ways.

GRR= Total fertility Rate x population of female birth; by using the sex + birth which is 105 males out of 100 female fro population of female will be 100/205 if 100 for females + 105 (males) = 205

.i.e.      100     =          0.4878

            205    

GRR    = 7.3 x 0.4878

            = 3.6 daughters.

NET REPRODUCTIVE RATE         

This is the average number of daughters that will be born to the cohort of women if they experienced ASFA + mortality rate

NRR > 1 population is capable to replace itself or a faster rate

NRR    =          Birth female    x          Σ Birth Age(x)             x  1 x

                        Total Birth                   Female Age(x)          10

                        1                                  1                                   life

                        Ratio at Birth              ASFR of Female       Table 10

                       

(viii)         GENERAL LEGITIMATE RATE

GLR=       legitimate birth      x 1000

            Married women 15 – 49

(ix)   GENERAL ILEGITIMATE FERTILITY  RATE

GIFR=     General  illegitimate fertility rate   x  1000

            Single widowed, divorced women 15 – 49

MORBIDITY AND MORTALITY

·        Morbidity refers to a state of illness and disability in population

·        Mortality is a process whereby deaths occur in a population

·        Death is defined as permanent disappearance of all evidence of life or any time after birth have taken place therefore death can occur only after a live birth.

·        Definitions of death excludes deaths which occurs prior to live birth e.g. foetal death; data of morbidity  and mortality describes causes of diseases and deaths; normally death statistics are needed for population studies public health services; the quality of data absent death is largely affected by the vital registration system and this may be due to failure to cover the geographical  areas especially to LDCs  or it may the result of the problems  of geographical  location of events of death due to concentration of hospitals in large towns, for example Muhimbili in Dar es salaam, Bugando in Mwanza, Mbeya Referral Hospital etc

DETERMINANTS OF MORTALITY

Basically these are 3 main determinants of mortality sex, age and social economic status.

SEX

Generally males have high death than females, although the sex ration indicates that  age are more males children vise versa is true in elder ages; this is due to biological build up female are made of type of genes XX while males are made by XY genes; for example life expectancy at birth male in 1988 males were 53 years and females were 55 years in Japan were 77 for males and 81 for females.

Exceptions occurs in areas like India where high rate of females mortality are observed and this is probably due to gender equality in the society at the expense of women

AGE

Mortality is closely related to Age in many developing countries child mortality is higher than at middle ages.

Diagram
SOCIAL ECONOMIC STATUS

This generally relates with the levels of income occupation environments, education, health services, housing condition, nutrition, security etc.  Societies with higher/better socio- economic status normally have longer life than society with poor socio-economic status

CAUSES OF DEATH

·        A cause of death is normally illness or injury which is one way or another lead to death sometimes the certification of  death by causes is not easy due to the fact that several conditions contributes to death.

·        In such as a case international classification of diseases recommends that multiple causes of death should be applied.

·        It is advised that a death certificate should outline the sequence of events which led to death and designate one of them as underlines causes of death and the other immediate cause of death, the underlines causes in different to immediate causes of death may be categorized in primary/principal and secondary of contributory or associated causes.

·        The international classification of diseases classify causes of death into 150 and can be abbreviated to 50 this can also further abbreviation to 5

Diagram

GROUP I:

Consists of infections and parasitic diseases such  as respiratory diseases, TB, Malnutrition etc, and this is very common in LDCs because of low medical development and health services. Also expectancy and standard of living of people improve those diseases are replaced by degenerative diseases such as cancer and cardio vascular diseases;

Generative (Exotic) diseases refers to the infection diseases like Malaria,Cholera,which are due to favourable parasitic breeding environment.

Degenerative (Endogenic) diseases are like cancer which are caused by intoxication of industrial processed food stuffs and as well as chemical drugs.

GROUP II

Includes diseases like cancer and which are common in developed countries

GROUP III

Includes circulatory system like lungs, BP, heart diseases, stroke and so on.

GROUP IV

Includes violence or injury which is mass predominantly in developed countries because of technical development.

GROUP V

All classified diseases this means that all diseases which cannot be categorized into any previous              group.

MEASURES OF MORTALITY

1.         CRUDE DEATH RATE (CDR)

This is the Ratio of deaths in a year to the total population expressed per 1000 people, Like crude birth Rate it is conventionally expressed per 1000 people. 

CDR =             Deaths in a year                                x 1000

 

                        Total population (mid year population)

i.e. for every 1000 people there is a certain number of deaths this measure is a poor measure of mortality as it doesn’t take into account of  Age structure;

e.g. in 1998 crude Death Rate in Tanzania was only slightly higher than UK while the life expectancy was 51yrs for Tanzanian while it was 72yrs for United Kingdom.

2.         INFANT MORTALITY RATES (IMR)

This mortality of life born infants who have not reached their 1^st birth day.

v Is a measure of deaths of children under 1year per live births in a year expressed per 1000 people.

IMR =              Deaths under Age one in a year     x 1000

                       

                        Life birth in a year

In LDCs infant mortality is a major contributor to deaths while it is almost negligible in DCs which have achieved remarkable improvement in food and infections disease control. Infant mortality rates normally range from 7-15 in developed countries (DCs).  While in poor countries vary from 50-200 per 1000 people.

e.g. Sweeden there were 98, 463 births in 1995 + 666 infant deaths.

IMR =              666 x 1000

                       

98.463

IMR =              6.8 per 1000 children

While in Developing Countries total births ranged to 104, 000, 000 and 9,500,000 infants

IMR =              9,500,000      x 1000

 

                        104,000,000

IMR = 91

With the infant mortality a number distinction are made according to age of birth and causes of deaths of infants.

3.         NEONATAL MORTALITY RATE (NMR)

These are deaths occurring during the 1^st year of the Life. It tend to be centralized in the 1at or one month.

·        During this early weeks the causes of infant death lead be different of birth which occur later of this the NMR is often broken down into 3 parts which are early Neonatal Mortality Rates take mortality Rate, + Pits Neonatal Mortality Rate.

·        Early neonatal mortality rate

A ratio of deaths of children under one week over life birth of children Aged one week per 1000s.

ENMR =          Deaths of children under 1 week                x 1000

 

                        Life birth of children aged one week

POST NEONATAL MORTALITY RATE

Is a ratio of deaths of children aged 4 to 52 weeks over life births aged 4 to 52 weeks.

 PNMR =         Deaths of children aged 4-52 weeks x1000

 

                        Live births aged 4-52 weeks

·        This division of infant mortality is done deliberately to insulate exogenous causes + Endogenous causes of deaths such as accidents + parasitic or infections diseases; while endogenous causes is mortality attributed by ages. 

·        Endogenous causes tend to be stronger during the early neonatal period which Exogenous causes are stronger during the post Neonatal Mortality.

THE LATE FOETAL DEATH RATE (LFDR)     

Is popularly known as still birth (unborn baby death)

LFDR =           Late Foetal deaths             x 1000

                       

                        Late Foetal deaths + live

·        However there are problems with identification of foetal death or still birth but World Health Organization (WHO) defines still births to occur after 28 weeks of Gestation.

·        The deaths which occur before 20 weeks are called early foetal deaths + those which between 20-28 weeks of gestation are called Intermediate Foetal deaths.

CHILD MORTALITY RATE (CMR)

This is the Mortality that occur to children between 1-5yrs; This measure is normally taken because of great differentials between infants and children above 1year, these are largely caused by social factors like Negligence of children after winning them, or lack of  substitute of the mother’s breast feeding,

·        In most of 3wc to the presence of  sever malnutrition

CRM =            Death of children 1 – 5yrs                x 1000

 

                        Live children aged 1-5yrs

(Also deal with under 5 Mortality + Age specific Mortality Rate)

MATERNAL MORTALITY RATE (NMR)

This is generally defined as the number of death due to puerperal (birth complication)

MMR =            Deaths due to puerperal      x 1000

 

                        Live birth in a year

Maternal deaths in developed Countries are below 10 deaths per 100,000 live births while in developing Countries it was be over 200 per 100,000 live births.

BASIC POPULATION THEORIES

DEMOGRAPHIC TRANSITION THEORY (DTT)

Introduction

Fertility and mortality are 2 major demographic aspects that are based on population growth, the theory states the Trends through which the World population has been passing through. Introduced by Thompson Wallen 1829

·        DTT draws experience from fertility and mobility that occurred in Western Europe, the change in mortality in Europe were mainly the consequence of industrial, Agricultural + sanitary Improvement in the 17^th – 18^th C.

·        The major assumption of the Theory is that changes take place in birth + death and a population passes from tradition to modern Economy.  This assumption works into 2 premises.

(i)                  Fertility and Mortality are high in traditional society and low in modern societies

(ii)                Every modern society passes from high rates of mortality + fertility to low rates of fertility + mortality.

Diagram

The development of the Theory is shown in the following features.

STAGE I BEFORE

19^th_c characterized by high fertility + mortality both rates- birth rates + death rates fluctuate at a high level (about 35 per 1000) giving a small population growth almost stagnant population growth rate of about 1% per annual.  Birth rate are high because of no birth control or family planning so many children die in infancy that parents tend to produce more in the hope that several will survive; many children are needed to work on the land, children are regarded as sign of virility and some religious beliefs (Roman Catholic, Muslims and Hindus) encourage large families.

High death rates especially among due to; Disease and plaque (bubonic cholera, kwashiorkor), famine, uncertain food supply poor diets, poor hygiene, no piped, clean water and no sewerage disposal and little medical science, few doctors, hospitals and drugs.  This stage occurred between 1800-1840.

STAGE II

The stage began in the 1^st quarter of the 19^th probably around 1840, at this stage birth Rate remain high but death Rates fall rapidly to about 20 per 1000; people giving a rapid population growth (population explosion) this is due to improvement of health services, food supply, scientific drugs, sanitation and water supply.  This stage whose several Developing Countries are experiencing after the introduction of Western Medicine but the only different in the Developing countries it is not accompanied by industrial development.

STAGE III

Began on the late 19^th C, Birth rates now fall rapidly to purges 20 per 1000 people while death rates continue to fall slightly (15 per 1000) this giving a slowly increasing population; this is due to wide spread of modern economic growth and the introduction of modern family planning programme; However it is important act that birth Rates and death in this stage due to late marriage, celibacy and other social economic.

STAGE IV

Began in the 2^nd half of 20^th C probably in 1970 reversed with birth Rate fluctuating the death Rate; stage IV is a part of stage III here the population is experiencing “O” growth or below replacement level; This is due to the present population structure, of developed Countries with more aged population as result the Net reproductive Rate in some of the Country is less than one.

POPULATION HISTORIES IN THIRD WORLD COUNTRIES

Introduction

The Demographic translation in developing countries late probably 1900 when most of the people were living in a substance level; The birth rates in developing countries today are considerably higher than the pre-industry in Europe; This is because of Universal and early marriage; Both people in LDCs marry at early age than pre-industrial Europe thus there are more years to have children especially in 1950-1960s.

Stage II of DTT occurred thought the Global, this resulted from imported modern medical and public health technologies hence birth rates in LDCs fall much more rapidly in 19^th C Europe, The birth rate is more than 40/1000 in many countries demographic transition remain X-rized by population growth rate about above 2% per annum, the result of stage III these are 2 broad classes of developed countries.

CASE A

There have modern method of Birth control combine rapid and widely distributed rises in the level of development the death Rate has Fallen and Below 10 per 1000 and birth rates are falling rapidly ties between 25-30/1000 these are new industrialized Countries (NIC) such as Taiwan, South Korea, Chile, Sri-Lanka, Singapore, Mauritius, Hong Kong and Palestine.

CASE B

Most LDCs fall wider category, this is because after and initial period of rapid decline in mortality further decline on death Rate doesn’t occur due to persistence of high birth Rate as a result of these below levels of living causes an overall population birth Rate remain relatively high leading population explosion as what happened in Western Europe during the second stage; The countries include Latin in the stage II Asia, Middle East and Africa are still in the stage II of Demographic Transition.

LIMITATION OF THE THEORY

1.         The Theory was developed in Europe and so it is more applicable in Europe (Euro – Centric), Hence most LDCs will never attained what happened in Europe.

2.         Least Developed Countries will not manage to suppress population through imported technology

3.         Even in Europe Demographic Transition Theory didn’t follow the same trend e.g. in France and Sweden fertility declined earlier than mortality.

           

MODELS AND THEORIES OF MIGRATION.

               A: CLASSICAL THEORIES OF MIGRATION.

(1): RAVENSTEINS THEORY (RAVENSTEINS LAWS OF MIGRATION)

·        The development of migration Theories and models started with revenstens in 1885 when he outlined the so called laws of migration in paper presented to the Royal statistical society (England)

·        This Theory stated the main xstics of migration and their Relationship to the physical environment and level of development of an area; According to Ravestein migration will differ according to physical condition of a particular area; Also migration is very much related with a level of development of a particular area, that is why the mobility in the developing countries is very high.

·        According to Revenstein migration can be summarized as follows.

(i).        Most migrants move short distance only but those who opt for long distances  

move to great centre of commerce and industries.

(ii).       Migration was a sex selective for females were more premedical at in short distances migration which means the opposite for males, also males are more prone to migration that females because in Normal societies females are more controlled than males.

(iii).      In terms of volume of migration the volume of migration increases as the Technology develops.

(iv).      There is a dominance of economic motives in migration other aspects like social services, wars, relatives; flood and son can not predominance to economic motives.

(v).       Where there is stream migration these is a counter stream in most occasions  stream migration Regenstein used the 1881 UK census to develop this Theory and laws of migration.

(vi).      Migration goes by stage

APPLICATION OF THE THEORY

1.         It is true that most of the people move into neighbors’ regions e.g. in Tanzania these are great Inter-regional migrations; those who opt to move they move to Dar es Salaam because of commercial activities and industries.

2.         Dar es Salaam has many males than the females also in Pemba South because of Industrial and Commercial activities.

3.         The volume of migration increases as technology develops, the higher                  development in Technology the higher connectivity and higher interaction.

4.         Stream migration is greater than counter migration.

5.         Normally people move and settle to small centres before they decide to settle to great centres.

CRITICISMS OF THE THEORY

Ravenstein turned social science laws to physical science pure science law which is not true e.g. it is not necessary that women must move short distances; However his laws are highly applicable.

(2): GRAVITY MIGRATION MODEL

In 1930-1940s various studied tried to familiarize Ravenstein Theory on the role of population size and distance in determining interactions into the gravity model basing on Newtons law of Universal gravitation which states that “two bodies in the Universe attack each other in proportion to the product the square of the distance between them”.

Diagram to show the way how Gravity Model works.

Gravity call it must that people from centre 1 will move to centre 2 the volume of migration will be determined by distance this means that the closer the distance the higher the volume of migration.

Zipf (1948) modified the Gravity model by formulating the population distance theory; he used the application of Gravity model on social interaction by regarding the movement of goods, people and information as an expression of the least effort whose inter community movements minimizes the total work of the system and introduced the formula.

Mig =   Kpi:di   whose by

            Dij:       M =                  Volume of movement between 2 communities

                        (and) =            product of population

                        Dij =                 Highway distance between ij

                        K =                  the proportionality constant

WEAKNESS OF THE GRACITY MODEL

  ● The model is more mathematical oriented in such a way that it assumes that there is  no resistance of population from the area of origin like water flowing from the load to the sea.                                                                                                                                                                                                                                                                                                                          ● It does not put into account the return migrants.

● It ignore the positive and negative factors of migration like cost of migration and obstacles before any decision to migrate is made.

●It doesn’t do much to explain the motives for migration.

APPLICATION OF GRAVITY MODEL TO AFRICAN

●At international level most of the migration occurs among the neighboring countries.

●At National Level there is intensive Inter-regional migration between neighboring

   region.

●Primate cities like Nairobi, Dar es Salaam also Addis – Ababa and Kinshasa and Johannesburg are great centre of commerce and industries pull migrants from all over the countries and beyond.

●The gravity model is rarely a good predictor of flows of migrants.

●The model explain as to why the real figure is different in terms of population.

                                  

                        (3) INTERVENING OPPORTUNITIES MODEL

Introduction

The Intervening opportunities model was introduces by Stouffer in 1940 as the criticism of Gravity model which has its major assumption that people are moving to new station due to gravity (distance). The major criticism is that; linear direction purse is not the determinant of direction pattern than the nature of space in the area of migration.

He argued that distance should not be treated as the main reason of migration but as social economic determinant since migration is costfully both socially and financially; the migrant will not migrate if there are not opportunities like employment and other Environmental amenities between the area of origin and destination i.e for number of people going into a certain direction will be directly proportion to the number of opportunities.

Y =        x

             X

           

y =       kx

 

            x

where as:       y =       Expected number of migrants from a particular zone/place

                        x =       Number of opportunities within the area of destination

x =      Number of opportunities between the area of origin and midway to the area of destination

                        k =       the proportional constant.

After criticism he changed the formula

Y =      k x 0 x i

 

            XB XC

Whereby:       K =      the proportional constant

                        Y =      number of migrants from city one to city 2

                        Xo =    all out migrants from city 1

                        Xi =      opportunities in city 2 measured by total in migrants

                        XB =    opportunities intervening between cities one and two measured by                                                                                                                                                                 

total migrant to a circle having a diameter of the distance from city 2 to city one.

                        XC =    number of migrants competing for opportunities in city 2.

CRITICISMS OF THE MODEL

1.         Model didn’t introduce anything new from gravity model, rather it just defined some concepts.

2.         The use of Intervening opportunities instead of distance adds some very little in predicting migration.

3.         People’s knowledge of opportunities to migrate decreases with increasing of                       

            distance

    

4.         It doesn’t explain why some fertile areas like Nyasa and Western province in Kenya or Southern Highlands and Lake Zone in Tanzania are major areas of migration.

APPLICABILITY OF THE MODEL

Studies in some areas like South Korea, Cuba, and Senegal shows that satellite Towns

(Small developing loans like the mege city) have successes in reducing the rapid growth

 Rate of the primate cities like Dakar in Senegal, Havana in Cuba and Seoul in Southern

Korea.

B: NEO – CLASSICAL MIGRATION MODELS

 (1): PUSH AND PULL MIGRATION MODEL:

This model was introduced by Sir EVERES LEE (1966) it was introduces after classical model seen to be very abstract.  The main factors of migration which made an individual or group of people to decide to migrate.

The theory assumes that in every area there are positive and Negative factors encourage and discourage to live that area; The area of origin may include property ownership like land, House or physical condition like good climate; disease; there are other factors which includes war, bad climate and disease; there are other factors which are classified as zero which make people not decided whether to migrate or not to migrate like Law, education attainment, marriage.

 Diagram

Negative and positive factors are found both at the area of origin and Destination; However for someone to migrate positive factors at the area of destination must be stronger than that of the area of origin. Negative factors at the area of destination may be the results of lack of employment and Assimilation so migrants may be forces to return to the area of origin.

Between the area of origin and destination there are intervening obstacles which may be slight or very bit for instance; distance, transport and physical barriers like ocean and mountains.

Furthermore there are many personal factors which affect Personal decisions to migrate some of these are associated with Age structure eg age entry to labour force and also marriage.  Others depend on personal xstics of any individual as for some people in order to migrate there are must be a compelling reasons while for others just a little promise is enough to make them to migrate; furthermore all people who migrate reach the decision themselves like a wife, children therefore migration not always Rational.

         Therefore; according to this theory the factors for migration include:-

                ● Age structure

                ● Marriage

                ● Decision making e.g. Wife and children.

                ● Transport

                ● Distance

                ● Employment.

                ● War

                ● Diseases

                ● Climate

                ● La ws

                ● Education. Etc

                  

              

APPLICABILITY OF THE MODEL

This model is very simple to understand and interprete i.e. the model doesn’t work on abstract like the classical models.

(2): Dual Economy Model

This model was introduced by Lewis 1954 and later developed by Grand in 1961.

The model divided the economy of the developing nations into two major sectors.

(i) Traditional sector.

Marginal productivity is almost Zero and thus it has surplus of labors. Workers are paid very low wages which is almost the same as their subsistence level. This sector is dominant in rural areas where agriculture is more practiced. Since in rural areas there are surplus labor, the labor will be gradual transferred to the modern sector where the average wage is above traditional sectors.

(ii) modern sector

 Is based in urban area where the main activities is industries, commerce and transport sector.

  ●it has high wages that continue to pull workers from traditional sector.

  ●strengh of the modern sector which makes the urban areas to continue to attract

     migrants from rural areas or mega cities.

  ●large economic base attract migrants from both rural and small towns.

               CRITICISM OF THE MODEL.

●In many dvping nations rural- urban migration is increasing despite the high level of urban unemployment. Therefore much applicable in Europe essipentially during industrial rvln

●The industries which are established in developing countries continue to narrow employment opportunities.

●Under estimate the capacity of agriculture in increasing labor productivity and absorbing many additional workers.

●In most cases agriculture is the main source for capital for establishment of non-agriculture. However during the peak of working season labor in agriculture are highly needed.

     APPLICABILITY OF THE MODEL

Countries will transfer their industries to developing nations where labor is cheap.

It is true that agriculture is dominant in rural areas where by the productivity is almost for subsistence.

In modern sector it is true that commences and trade is dominant.

In urban sector the wages that the labor are paid is obviously high.

In dvpng nation the established industries have narrowed employment by making the unskilled labor not to be enrolled in modern sectors.

C: THE POLITICAL ECONOMY MIGRATION MODEL

Analized migration as the change of social structure in the society.

(1): CENTER PERIPHERY MODEL ll (Amin, 1974)

Argue that the problem of migration in Africa is mainly caused by transformation and disruption of underdeveloped traditional economy.

The center periphery relationships lead to the unequal rural-urban migration.

For instance, primary products/crops like coffee, tea, sisal, mineral and parts export labor to the export dominated sector; those parts are called labor reserve. Actually this will make the difference in terms of migration.

(ii): SURVIVAL/FAMILY LIFE STRATEGY THEORY (Meillassoux, 1981).

It argue that selling  of reproductive labor in the traditional sector is essential for sustainance of the capitalism. So migration is just an outlet for the rural workers to survival by providing cheap labor to the urban capitalists enterprises. At the same time migrants are forced to maintain their links with rural areas b’se the modern sector dominated by the foreign. Capital which does not give them the social economic security.

Another scholar called Stahl 1981 explained the model by observing that rural families used rural- urban migratiomn as weath of miximization through remittnes, usually both family which adapted survival strategy belong to the poor social economic strategy and so it is necessary for  some member of the household to migrate in order to generate income for a survival of household.

 MOBILITY OF MIGRATION THEORIES

This analyses the main types of mobility/4ms. They observed that, migration often involves a permanent change in resident can be termed as “circulation” and this circulation include the great variety of mvt which in most occasion are short term , repetitive or cyclical in character. All these term have the same x-ter.

Furthermore circulation can be divided in; daily, seasonal, periodic and long term circulation depending on the length of circle.

(i); The theory of mobility transition (Zelin Sky, 1971)

This has the following categories of migration;

              Rural-rural migration

              Rural-urban migration

              Urban-rural migration

              Urban-urban migration

(ii): SYSTEM RURAL – URBAN APPROACH MODEL     

The model introduces by Akimu Mabagunje (1970) he considered that Rural – Urban Migration is a process which links rural societies whereby main economic activities is agriculture with Urban areas, The urban areas are more complex and specialized in Industries and commerce the spatial movements Transformation of skills and motivations and behavioural patterns these changes enable the migrants to change his/her rural background and become urbanized (urbanite) i.e. join the urban.

                                    Rural ®Urban

Agriculture Complex specialized, Industries and commerce, change skills, knowledge

and behaviour.

The process of interaction is composed by elements in a given environments which comprises a certain variables of chancy which affect a system e.g. villages which is more exposed to urban can experience more Rural – Urban migration than a closed village, these are strong link between Rural – Urban economy which finally end up by integrating the  economy the systems operates into 2 systems.

                                                    LINKS

RURAL SUB - SYSTEM.

This is based on rural areas and its economy is largely agriculture. It has its own control mechanism e.g. family or community which may allow migration or minimize migration e.g. some societies females are not free to migrate, also the kihamba system of Wachaga do not allow the last  born to migrate.

THE URBAN SUB SYSTEM

This operates in Urban areas it is more specialized and complex it encourages and discourage people to migrates into them because of housing and employment; it is largely controlled by the government it is linked with Rural Sub System with visitation,

                                                             Feedback

Urban sub system

Rural sub system

                                                                                                                            

                                                       Return migrants                                         

              

                  Weakness

                    →It not true that everyone who migrate to urban must totally be  

                          Urbanized in all aspects.

                    →It ignore the influence of rural culture in urban areas.

                   →Not true that in urban areas all natives are practicing agriculture but                                                                                                                                          even trading activities may be  taking place.

                            

Question:

Using one model of migration examine Rural – Urban migration.

                                         

                                        END OF TOPIC 3

                 TOPIC 4:  POPULATION REDISTRIBUTION IN TANZANIA

SOURCES OF MIGRATION DATA

The main sources of migration data in Tanzania is census. Tanzania has conducted a modern censuses as source of modern demographic data is conducted census in 1748, 1957, 1967, 1988 and 2002; Zanzibar started in 1961.

This given a reasonable coverage of migration data although it lacks some comparability between census.  Therefore census migration data in Tanzania is less accurate and comparable due to the following reasons:-

1.      Before independence census data was taken on tribe basis these data give only some clue to the place of origin of migration :-

·        It also numerated the whole stock of migrants of which includes children born by migrants or the place or residence, However it has disadvantages as it did not locate tribes which cover several administrative regions like the Wasukuma and the Masai

·        Also it can not solve confusions resulting from re-marriage and assimilation, also in the area of destination there is a Tendency of ignoring of small tribes for the same region which may be ethnically different from by tribe e.g. Tribes from Iringa region may be categorized as Wahehe while these is other small tribe like Wakinga, Wawanji and wapangwa.

2.      Changes in Boundaries of Administrative area before independence Tanzania has provinces which were Tanga province southern Highland province, Southern province, western province central province the census of 1967 Tanzania had Regions and not provinces in 1978 Tanzania has 20 regions 1988 it had also 20 regions in 2002 it has 25 regions the number of districts has been also increasing from time to time, therefore these date need to be reconstructed.

3.       Changes in the place of birth and residence the place of birth data has some limitation as migration indicators this is because it carries no information about step wide migration and return migration it does not ask question before being at the place. e.g.  in 1967 census migration was categorized in the following order:-

·        Some region locality (Born in the same place)

·        Some region (Born outside the region)

·        Other region (Born inside the region)

4.      Another problem is related to deferent of migration and non migration especially in Defector census carried out in Tanzania Generally in  Defector census temporary visitors  to a place outside the place of birth are classified as migrants and those who visiting their original home areas appears as non – migrations.

5.      Change of in deferent of what called a town or urban in 1978 all Regional and District capital were regarded as town some capital had population of < 2000 and it has poor infrastructures also for a mixed population it is difficult to categorize Rural/ Urban.

6.      Absence of National Vital statistics registration these makes difficult to establish the spatial variation in the net each or less in population in a given area due to migration these problems limit the use of measure like sex ratio to show major areas of in migration and out migration.

  

INTER ZONE AND INTER REGIONAL MIGRATION

Basically it is divided into 2 parts before independence and after independence both inter zone and inter regional migration are divided into these two parts.

BEFORE 1961

·        Oral History shows that the major ethnic groups in Tanzania like the Bantu, cushities and Nilotes had migrated from a certain core zone areas within Africa and outside area  for example the Nilotes is known to be originated from southern Sudan cushites  originated from Iraq and the Bantu originate from Congo areas and spread all over the south  of the squatter is also  documented that LDT by Tribes like Yao and Nyamwezi  as well as the slave trade has played an important  role in population redistribution of coastal and interior tribes in the 19^th c.

·        During the colonial period migration was dominated by establishing and development  of large scale plantation, mining and industries the colonial government stimulated movement of  labourers to area of wage employment. The core areas of development were large located in towns coastal heater land and some highlands area in the North East.

·        In 1947 about 300,000 labors were employed in manual labour in various establishment, Although some wage labour settled in areas of wage employment  in its impact on population distribution was minimal because most of the migrants did not like permanent residence these occurred because most of migrants were single male and always returned to place of origin after certain interval of works; however due to sex selecting it caused regional sex – ration imbalance which had economic and demographic implications such as delays in marriage and absence of labour force in the subsistence economy.

·        An analysis of the census carried out in 1948 and 1957 shows that the core areas of development during that time were range and Northern Provinces which includes Kilimanjaro and Arusha.  The areas experienced net migration gain where as central southern Highlands and western provinces had negative net migration; no clear net migration gain or less was observed in Eastern and lakes provinces because the Eastern province the gain in Dar es Salaam and Kilosa Districts were lowered with the loss of other districts.

·        In general there was an overall relationship between area of later supply and demand with areas of net immigration and net out migration these patterns produced traditionally so called labour reserved which existed through our the colonial period and wage employment.

·        In the labour reserves the main tribes which had large  number of population at a work within the country included west province which included Waha, Wafipa, Wanyamwezi, Wamambwe; central province included Wagogo, Wanyaturu and Wanyiramba, Southern provinces included Wangoni, Wanyasa, Wayao, Wamakua, Wadigo, Wamakonde and Wamwera, Southern  Highland included Wakinga, Wabena, Wapangwa, Wasafwa, Wanyiha, Wanyamwanga, Wamade and Walambwa.

NOTE: Some population wage employment existed in Southern Highlands provinces with Tea and Tobacco in Iringa districts, in Mtwara there was groundnut scheme in Lake Province the pocket wages based on coffee growing in Bukoba District and cotton growing in Shinyanga and Mwanza districts. 

INTER ZONE AND INTER REGIONAL MIGRATION 1961 – 1988.

The historical background migration before independence shows that the country was divided into 2 zones that is developed zones which were treated as gaining zones and the less developed zones which were treated as loosing zones; the analysis of internal migration between 1967 – 1988 shows that the following features:-

1.      Eastern zone comprising Dar es Salaam, Morogoro and coastal regional these zone increases its net migration gain from about 120,000 lifetime migrant in 1967 up to about 450,000 migrants in 1988 the main contributor being Dar es Salaam and Morogoro, Dar es salaam was because it was the main commercial and industrial centre of the country, Morogoro also contribute to positive migration net gain because of industrial development as results of industrial and commercial decentralization from Dar es salaam, also development of infrastructure like HEP supply in Kidatu, expansion of sugar plantation in Kilombero and Mtibwa and the TAZARA Railway, from Tanzania to Zambia.

However as a challenge to labour concept coast region had negative net migration despite being localized in Eastern zone.

2.      North Eastern zone i.e. Tanga, Kilimanjaro and Arusha during the peak of plantation economy in 1967 Tanga and Arusha region has a strong net migration but when the plantation economy collapsed or 1960s it was only Arusha region which increased its positive net migration because its be strong base in industries and more land for settlement form densely populated neghbouring region like Kilimanjaro, Arusha experienced positive net migration from about 58,000migration in 1967 to about 141,000 migration in 1988; on the other hand due to population pressure Kilimanjaro Region increased its net Migration loss from about 11,000 in 1967 to about 124,000 in 1988.

                                                      

Tanga region persisted to a net migration gainer up to 1978 because there was deliberate effort by the government to prosper the economy of Tanga by building industries; however in 1988 Tanga recorded net Migration loss of about 51,000 life time migration, this is due to delay of plantation especially of Sisal and Tea  plantation and returned migrants.

3.      The western zone comprises Tabora and Kigoma; the establishment of settlement schemes with Tobacco as the main cash crops in 1960s made Tabora Region and the zone to register positive net migration in 1967 but the decline of Tobacco prices in the world market and lack of land for new crops made the zone relapse into Net migration loss and more loss was experienced by Kigoma region in 1988.

4.      The Southern zone Lindi, Mtwara and Ruvuma the southern zone has always been net migrant losing zone of lost about 72,000 people in 1967 to about 160,000 in 1988 mainly is due to the poor infrastructures and the situation in the present is very worse.

5.      The central zone Dodoma and Singida, Despite the location of the capital of the country in Dodoma the zone has always increased its negative migration from about 45,000 migration in 1967 to about 159,000 people in 1988 this is due to poor climatic condition.

6.      The southern highlands Iringa, Mbeya and Rukwa, the zone registered a decreases in net migration loss in 1988 due to the decentralization which built several industries in Mbeya town the construction of infrastructure like TAZARA and Dar es salaam Lwaka Highway also stimulated trade between people from neighbouring countries like Zambia, Congo and Malawi; however this zone has contradictions in terms of core periphery relationship Mbeya region is gaining while Iringa is loosing to its neighbouring regions of Mbeya and Ruvuma, Rukwa neither looses nor gains.

MICRO-LEVEL STUDIES ON MIGRATION

Gulliver (1950 studies the Ngoni, Ndendeule, in 1957 studied the Nyakyusa, He realized that the majority  of people of these tribes were migrating in plantation, most of them were employed  in sisal plantation in Tanga and Eastern province;

·        Most of the migrants migrated to plantation because  the sisal industries were paying a better wage and also provided free transport  and food; however with the discovering of copper in Zambia and Gold mines in South Africa there was a big change in direction of migrants, they migrated to these new mining areas they migrated because they wanted to earn money so as to buy goods like clothes, bicycles, gramophones and for paying bride price, however  those  who migrated several times and were unable to settle down especially in Nyakyusa were despised by the whole community

·        The other popular destination was the Southern Highlands where most of migrants were employed in the coffee and tea plantation in Mbeya, Iringa and Rungwe district, However the destination in Southern Highlands were not popular because of low pay and also were not conducive to the migrants to serve from their wages these migrations generated conflicts between old generating and new generations because the new generating migrated much and those who were doing local activities were being laughed, also singing during the right caused conflicts

·        Lwoga (1955) and (1998) he studies about migrants to plantation with special references to Ludewa he noted a change in pattern of migration during the post independence period, he realized that there was shift of migration from long tern to short term migration most migrants moved from Ludews to Songea and Usangu plain where they became causal labourers the reasons were:-

1.      Plantations economy were delaying hence they had no other alternative.

2.      The post independence government introduced cash crops to labour in reserve areas so as to discourage out migration e.g. tobacco in Songea and Tabora.

3.      People were earning more in causal labour than they could in plantations; he came up with the comment than unless there is heavy investment in labour reserve areas migration vicons circle will continue to grow.

Mbonile (1990) studies the migration among the Wakinga, he discovered that most of people migrated from rural to urban he also discovered that the kinga has managed to break the viscous circle.  Circle of migration by becoming business people occurring large shops vehicles and buses.

Berry (1972) used development projects to study internal migration in Tanzania he looked on Manonga in Tabora, Ikoa, Irrigation scheme in Dodoma and Isimani in Iringa; He discovered that Manonga attracted many migrations from Mwanza and Shinyanga they settled for long period and abler the failure of the projects i.e. when the Dam dried they migrated out, Isimani being major producing area also attracted many people but after faced the problem of land degradation they moved out; Ikoa also attracted many migrants from within Dodoma and Singida regions but after the factor of the projects the migrants moved out.

Mayombo (1990) studies the impacts of structural changes in Kilombero valley in his study he observed the opening of Kilombero valley with more reliable transport system like TAZARA Railway line, sugar plantations and Kidatu HEP stations made the valley to pull the migrants from the whole country and in particular from Mbeya and Iringa, He also observed that besides employment people moved to new towns along the railway to establish business which were mostly run by females who were the majority of migrants.

RURAL – URBAN MIGRATION

Several studies based on study on Rural – Urban migration.

Saboti (1973) conducted a survey on urban mobility employment and income in seven towns of Tanzania, He discovered that there was a gradually drifting into urban unemployment problems; Although the unemployment was not observed among the skilled and most productive force members of the labour force it was estimated that about 20% of the total urban labour force had no employment; He also noted that migrants had an alternative or economic options in rural areas where retained only after a short period in the urban labour market; He also observed that the problem of unemployment was more serious among non-migrants who had no options of moving to rural areas.

In general he predicted that the problem of unemployment increase with time because of rapid population growth both in rural and urban areas leading to land and unemployment shortage, He also observed that there was a change in employments qualification with time during colonial period a primary school leaving certificate was enough for someone to get employment in modern sector.

However after independence the expansions of education changed the structure of educated manpower the market for waged labour decreased;  As a result post primary school leavers exceeded employment and began to fitter down into the lower jobs which employed primary school leavers, thus primary school education are replaced by secondary certificate and secondary certificate are replaced by University certificate.  He also noted that the number of educated people who returned to rural after missing urban jobs increased making less likely for primary school leavers and uneducated to migrate to town.

Mlay (1977) He made a study on in Migration in Moshi and Arusha town and noted that Rural – Urban migrants were more motivated by Economic reasons like employment in modern sectors whicle other factors like family ties desire for education and vocation training initrated the 1^st move only.

Mahindi (1980) discovered that Dar es Salaam being a capital city and major commercial centre of the country attracted many migrants from all over the country; He also found that Dar es Salaam was largely composed by migrants he also discovered that migrants had higher fertility than non-migrants.

Mbilinyi and Omari (1996) deal with rural poverty and migration of women (female migration) they found that poverty was the main factor for rural – urban migration they realized that the majority of migrants when reaching in urban areas they are employed in informal sectors and those who send remittances back home induce more rural – urban migration because remittances look more attractive to people remaining in rural areas.

Wangwe et al (1996) Discovered that rural – urban migration are mainly directed to Dar es Salaam city they also discovered that migrants participating in informal sectors do not serve thus they fail to go back to their rural areas, but those who engage in formal sectors serve and are able to go home thus had strong rural areas.

Rivinga and Makacha (1998) studies about wamachinga from Southern Tanzania they found that poverty was the main cause of out migration the most important factor which they paointed out is the negligence of southern region in development, this negligence had led to large number of Wamachinga to power into urban areas causing various urban problems.

Madale, Mwafupe and Mbonile they did different studies about migration at Usangu plain they discovered that the Maasai, Barabaig and Wasukuma are migrating to Usangu plain looking for pastures due to environmental degradagation and poor climatic conditions to their original areas.

Mwafupe and Mng’ong’o (2000) discovered that the Maasai are migrating into urban areas to work as guards, selling medicines and Hair dressing (weaving) due to land pressure as a result of encroachment of their land, environmental degradation, pressure of modernity whereby cows are no longer seen as a sign of wealth as well as poverty.

Conclusion: Inter-regional migration in Tanzania and Inter-regional population redistribution started strike prior to colonial due to long distance trade and slave trade.  During the period of colonialism was dominated by the concept of labour reserve whereas the labour reserves areas are under developed while other areas were invested and developed, the movement of people were from under developed to developed areas.

After independence people migrated from formally labour reserve to plantation, later due to delay of plantations economy situation change due to introduction of cash crops in areas formally regarded as labour reserve contributed much to changes of pattern of migration from long term to short term.  Establishment of various projects also led people instead of going to plantation they changed into these projects eg Ikoa, Isimani and Manonga.

Improvement of infrastructures particulary the TAZARA line if has influenced migration instead going to plantation they stoned to go to towns like Mbey, Songea, Kilombero ets.

Change of the type of economic activities for example Wakinga who now decided to be business people Wakinga now are not moving in long distance but moving to towns he establish business.

Low price of crops has contributed much to rural – urban migration and in general rural poverty whereby people hope that in town they will engage in informal activities in urban areas which contribute to the growth of informal sectors.

Environmental degradation and poor climatic conditions also is the main factor for migration particularly for position lists like Maasai, Sukuma, Barbaig etc who are moving to find good pastures for their livestock.

                              END OF TOPIC 4

                           TOPIC 5: INTERNATIONAL MIGRATION

International migration refers to the movement of people across the national boundaries which involves the changes of place of residence.  It is called immigration to a country of destination and Emigration to the country of origin; therefore those who are leaving the country are known as Emigrants while those who arriving in the country are called Immigrants.

TYPES OF INTERNATIONAL MIGRATION

International migration may be voluntary or forced migration voluntary migration occurs when migrants move from their own choice its mainly influenced by economic motives, forced migration is movements of people without their choice and it is resources, ethnic and religious conflicts, political instabilities, violation of Human rights.

At global level it is estimated that about 25 million people are refugees and out of this about 5 million are Africa.

DETERMINANTS OF INTERNATIONAL MIGRATION

1.         Economic motives (determinants) most of migrants move to other countries due to economic motives.

2.         Coercive forces just on rare occasions movements due to coercive forces like civil wars, civil disorders, political conflicts religion conflicts etc lead to generation of refugee.

3.         Social determinants like marriages, education and Health and social services.

MEASURES OF INTERNATIONAL MIGRATION

1.         Net migration is the balance of Immigration and Emigration

            i.e. NM = Immigration – Emigration.

2.         Gross migration is the some of Immigration + Emigration sometimes this measure is called turn over;

            Gross migration = Immigration + Emmigration

By using the above measures Net Migration + Gross Migration various ratios can be computed to show the magnitude of immigration + Emegration.

Immigration Ratio =               Immigration  x 100

                                               

                                                Emmigration

The opposite Emigration Ration =              Immigration  x 100

                                               

                                                                        Emmigration

CONTEMPORARY/CURRENT INTERNATIONAL MIGRATION

 

The international migration is determined by economic motives thus is largely labour migration therefore at global it consists of a services of micro-regional system that interact to certain extant these regional system can be divided as follows.

EUROPE

Due to her level of development Europe has been the main area of destination of International migration the collapse of Eastern Block countries has increased international migration of Europe the migrants to Europe mainly originate from all countries from south due to the following reasons.

1.         Fertility of Western Europe is below replacement level thus is dominated by old age hence need young people for labour force.

2.         Due to ethnic conflicts especially in Balkans.

3          Development of agricultural sectors in Europe the agricultural sectors in Europe has been developed simply because the sector is highly subsidized so it is no longer paying this employ cheep labour from developing countries there is under employment.

4.         Economic restrictions especially in Eastern Europe.

NORTH AMERICA

Canada and USA are very famous for destinations of International migration this is due to response of employee needs thus Immigrant in these countries must have business competitive as the countries are pressing emphasize on skilled labour migration, However currently they have introduced various laws to restrict migration.

MIDDLE EAST

This region has been affected by the Gulf war of 1990s, the Iraq war has created much migration in the Middle East countries like Saudi Arabia which also attract migrations from South Asia, in Saudi Arabia is due to its economy, which forced people to migrate to Saudi Arabia.

SOUTHERN AND EASTERN ASIA

The main regions which receive migrants are the new industrializing countries like Taiwan and Hong Kong; these countries are expanding the number of Immigrants.

Japan being one of the highly industrialized countries attracts migrants from Asia and other countries.

China also has a big potential as an exporter of labour followed by other countries like Bangladesh.

Australia and New Zealand, has been a traditional area of Immigration.

LATIN AMERICA

Is x rized by having higher Net migration, the volume of Emigration to North America is extremely huge it is estimated that 10 million people have migrated to North America and Europe within the continent there is migration from Columbia to Venezuela there is ethnic flows to Europe which is extremely common to people with origin of Spain who are returning back to Japan.

Mexico is one of the countries dominated by migrants because of its proximate to America.

AFRICA

On 1990s Africa had about 5.6 million International migrants out of 1/3 were from West Africa; In West Africa the major patterns of migration was people moving from remote regions and countries to coast Areas to work in Mining and plantations, the main area of thus destination in West Africa were Ghana Liberia and Ivory Coast the source countries were mainly Burkina Faso, Mali, Guinea and Niger.

EAST AFRICA

It has been the main course of destination of large number of refugees mainly from Ethiopia, Uganda, Somalia, Sudan, DRC, Rwanda and Burundi.

CENTRAL AFRICA

Mineral and Timber countries like Gabon, DRC and Equatorial Guinea has been the major areas of destination of migrants from neghbouring states like Cameroon, Burundi, and Central Africa Republic.

SOUTH AFRICA

The RSA has been the major recipient or destination of migrant labour from Botswana, Lesotho, and Swaziland on if the most important of labour in RSA is the flood of workers after the apartheid regime this is because RSA is the richest country in the continent, currently RSA is the major recipient of refugees in the continent; RSA catches at least one person out of 4 peoples who tries to cross the boundaries but they try again till they will successes.

IMPACTS OF INTERNATIONAL MIGRATION

1.         Impact on population growth, migration leads to population which may be large at small depending on relative size of migration and non migration.

The age sex characteristics composition of migrations increases growth rate in receiving countries, the steam of migration is higher among young ages and among males; the higher proportion of males may increase the opportunity of marriage for the indigenous women hence leading to higher population growth while is vice-versa to the country of origin.

2.         Impacts on Age structure, migrants crossing boundaries are predominately young males, therefore population structure of the area of origin will have few population of young ages particularly males while in the area of destination the Age sex structure will contain many people of young ages.

3.         Effects on labour force immigrants influence the relative size of labour force, it increases the labour force participation in a certain ages, on it may increase the inactive labour forces, In countries like Israel the level of Unemployment increases when people who claimed that they originated from Israel migrate in large number to Israel it has also happened in Canada when Idd Amin Dada of Uganda chased Indians from Uganda.

4.         Effects on employment and unemployment, immigrants usually increase unemployment problems while Emigration reduces the problem of unemployment, sometimes immigrations may help to break the bottleneck of the unemployment due to insufficient of domestic labour supply in a certain occupations and localities e.g. immigrants have solved the problem of marginalized jobs in Western Europe and North America.

            Immigrants are the ones who are working in dangerous environment or jobs           

           which needs intensive case like caring of the elders and people with manacle  

           disorder.

5.         Effect on wage levels immigrations usually may raise unemployment and greatly potential in lowering wages immigrations also may lead to low wages in receiving countries, than to the country of origin.

6          Effects on Balance of payment, migration directly affect the Balance of payment, the migrants may carry with them money for their survival and on their arrival to the country of destination they may use the money for investment there fore increase the balance of payment to the country.

Also migrants send remittances which contribute a lot of foreign exchange to their government e.g. India, Pakistan and Bangladesh social effects there are several problems associated with the international migration particularly to the receiving countries e.g they create congestion pollution of environmental degradation in general, shortage of social services, increase of crimes like robberies etc eruption of diseases etc.

Immigrant come with their customs so they face the problems of adjustment in new areas, they need to be assisted in their new environment, the absorptive capacity may be sometimes immigrants are frustrated and then may be get mantle disorder therefore migrants need to be assimilated and integrated into a new society.

7.                  Effects on resources; International migration can reduce pressure on resources to the country of origin or it may increase/crease pressure on resources to the country of destination.

8.                  Brain drain and Brown drain effects, Brain drain refers to the emigrations of skilled labour/people to the other countries and Brown drain refers to Emigration of unskilled forces, the main cases of Brain drain are Economic differences, between the countries, Employment Rates and Low wages particularly to LDCs as the result most skilled people move to other countries creating various effects.

                      IMPACTS OF BRAIN DRAIN

1.         Loss of skilled labour force/skilled people.

2.         Having expertise from the DCs

3.         Diffusions of technology when they come back or them software technology.

4.         The skilled people bring remittances to their origin countries hence improve the living standard of the people.

5.         It can control unemployment Rates.

6.         Increases wage levels.

7.         Brain drain is a source of foreign currency and also further brain drain

                                 END OF TOPIC 5

                                         END OF A COURSE GE 247 POPULATION STUDIES.