Friday, January 6, 2023


  Eli-express       Friday, January 6, 2023


Population refers to a group of people living in a particular geographical area at a specific period of time.

Population size refers to the total number of people living in a certain geographical area at a specific period of time.

As in 2002 population census, Tanzania has a population size of 36 million people.

Population growth refers to increase in the number of people living in a certain geographical area at a particular period of time.

It is divide into;-

a) National population growth – This is on the basis of birth rate and death rate and therefore it occurs when the birth rate exceeds the death rate.

b) Artificial population growth – This is brought about by emigration & immigration. This exists when immigration exceeds emigration.


It means increase of decrease in the number of people living in a certain geographical area at a specific period of time.


Change in birth rate

When the birth rate increase, population size also increase and when the birth rate decrease population size also decrease.

Change in death rate

When the death rate increases, population will also decrease and vice verse.

Change in immigration

When the number of the people entering the country increases, population will increase but when the number of people entering the country decreases, population will decrease.

Change in emigration.

When the number of people leaving the country increases, population will decrease but when the number of the people leaving the country decreases, population will increase.

Birth rate and Death rates

Birth rate refers to the number of the live birth per thousand people.

Reasons for High birth rate in law developed countries.

Cultural factor: In many low developed countries a big number of children is looked at as a source of wealth, prestige and increase during old age. In some cultures it is again a sign of strength.

Early marriage: in many low developed countries there is many instances of early marriages, where by girls and boys marry as early as 13 years which create a high possibility of giving birth.

Polygamous tendency: Many men have a tendency of marrying more than one wife which also contributes towards high birth rate.

Gender preference: in many low developed countries, couples have a tendency of targeting a certain gender and in the process they tend to have many kids.

Poverty: Children are looked as a source of income through bride price.

Early school drop outs due look of school fees, families cannot afford family planning facilities such as pills.

Ignorance: Many people in low developed countries are ignorant about the danger of high birth rate and also different precautions to be taken against unwanted pregnancies.

Idleness and lack of recreation facilities also contributes towards high birth rates since the couples are together most of the time.

Measures that have been taken by the Tanzanian government to control Birth rate.

Family Planning: The government has introduced family planning programs that are offered by many health centers all over the country at a very less fee.

Mass education: The government is also trying its level best to educate the masses to educate the danger of high population & high birth rate through political gathering, workshop, seminars etc under the concerned ministries.

The education policy: More schools have been constructed.

School fees have been subsidized

Sex education has been introduced.

The government also trying its level best to develop social and economic infrastructures in rural areas in order to reduce the idleness among people in rural areas.

The government has also used the law in order to reduce the birth rate as below;-The government set up sentences on rape on school pregnancies and it has also discouraged early marriage.


This refers to a number of deaths per thousand people per annum.

Reasons for high death rate in LDC’s

Poor or enough devices in number of ways

Lack of enough food supplies which has created a high level of famine and many have died.

Political Instability: In many LDC’s are experiencing political instabilities through wars, tribal conflicts, religious conflicts, which has result in many killings

Disease: In many LDC’s there is a lot of chronic diseases such as AIDS, TB, and Malaria etc which have claimed many.

Lack of enough medical staff

Lack of enough health center’s

Lack of enough hospital facilities

Poverty:- Poor nutrition, buy medicine

Poor sanitation and lack of clean water

Witch craft.

Population Density and Distribution.

Population density refers to the number of people per square km.

Effect of high Population Density

Negative effects

High rate of crimes.

Easy spread of diseases.

Low standard of living because of lack of enough goods & services.

Unemployment due to high supply of labor.

More pressure on social services such as schools, hospital etc

High rent due to shortage of houses.

Sanitation problems

More pressure on natural resources which result into environmental degradation.

Positive Effects

High market which will stimulate economic activities.

More labor supply.

Production will tend to be more competitive.

High government concern in areas with high population density.

Population Structure

This refers to the components of a certain population in a number of areas such as age, sex, occupation education etc.

Components of a Population Structure.

Age Structure: This is the distribution of population according to age and here population is divided into the children, adult and the old. The children and the old are regarded as the dependents (economically inactive) where as the adult are regarded as economically active.


Effect of High Dependency Ratio

High level of crimes rate.

It can result into increase in street children.

It can result into increase in government expenditure.

It result into low labor force.

It results into low savings and investment.


Poor nutrition

Poor sanitation

High occurrence of Disease such as Malaria

Poor Health services


Low level of education

Sex Structure

This refers to the distribution of population on gender basis ie. Males & females – from this we can know how many males & female that compare population of a certain country

Sex Ratio


This is the ratio between males and female

Sex ratio = males & female

Assuming Female are 6 and males are 2, calculate sex ratio.

For every 1 male there are 3 females.

Education Structure

This shows the distribution of population according to the level of s education i.e, the educated, the un educated and the various levels of education. It is on the basis of this that we can determine the illiteracy rate & literacy rate.

Occupation Structure

This is the distribution of population according to different occupations. This helps to know the number of people employed in different professions, sectors etc. It also helps to know the number of employed & the unemployed.

Income Structure

This shows the distribution of population according to different level of income and it is from this that we can know the number of those who are low income earners, medium and high income earners.


This is a situation when there is more and more old people as compared to the adults and the children.

This is the common feature for more developed countries due to high life expectancy.


It increases the burden to the government and society as such people become dependent, therefore the government and society has to spend more in providing services to such people.

Decline in the labor force which affects population.

Decline in efficiency of work as old people are always less energetic, both mentally and physically.

Increase in demand for goods demand by the old eg. walking sticks, spectacles etc but decrease in demand for goods for children.

Limited change in the society as the old tends to be more conservative.

Limited mobility of labor as many old is not willing to move from one geographical area to another.

Spatial Population Distribution.

This refers to how population is distributed in relation to the available resources.

There are three types of spatial population distribution;-

i) Over population

ii) Under population

iii)Optimum population

Over population

This is the situation when the number of people living in a certain geographical area is greater than the resources available. Therefore under such situation the labor force available is more than the resources available.

Indicators of Overpopulation

Low standard of living

Food shortage

Housing shortage

High level of unemployment

High pressure of natural resources which tend to result into environment degradation.

Congestion on social and economic infrastructure e.g. road, school etc

Optimum population:-

This is the when the population of a certain country balances with the amount of resources that are available, therefore the country labour force size can fully utilize the available resources.

Indicators of Optimum Population

There is full employment.

There is maximum standard of living.

There is adequate provision of social services.

There is maximum utilization of resources.

There is maximum output.


It is difficult to know that a country is at optimum population at a particular point because;

The stock of resources cannot be accurately known.

The population size may as well not be accurately known.

Time also affects the size of population and the stock of resources whereby they tend to change as time goes on.

Under population:- This is the situation when the number of people in a certain geographical area is less as compared to the resources available therefore the available labor force is inadequate to maximum utilize the available resources.

Indicators of under population

Small market size.

Low standard of living.

Shortage of labor force.

Under utilization and idle resources.



Positive Effects

Big labor force which can be used in exploiting resource.

Big market for goods and services.

Big source of revenue to the government through taxes.

High output produced in the economy and hence a high national income level.

It will also result into more competition in a society which will result into more creativity and inattentiveness.

Negative Effects

High level of unemployment due to excessive labor supply

High dependency ratio

Housing shortage

High rate of crimes

High government expenditure in provision of social and economical infrastructures.

More pressure on social services such as hospitals, schools etc.

High pressure on the natural resource which will result into environment degradation.

Excessive demand of goods & services which will result in to demand pull inflation

Life expectancy

It is the average number of years a person can live in a given country at a specific period time.

The life Expectancy in LDC’s such as Tanzania low as compared to MDC’s due to the following factors;-

a. Poor nutrition

b. Poor sanitation

c. High occurrence of diseases such as, Malaria

d. Poor Health services.

e. Poverty.

f. Low level of education.

Population distribution refers to how people are spread in a certain geographical area, therefore this can be even or uneven.


Social and economic infrastructures: – Population density is high in areas where there is availability of social services like hospital, education and economic services like roads, electricity, tap water and telecommunication while in areas there are poor social services and economic infrastructure the population density is very low.

Climate: Population density is high in areas where climate is favorable for the cultivation of different crops, examples of such areas in Tanzania are Kilimanjaro, Mbeya and In Victoria basis while in area where climate is unfavorable for the cultivation of different crops the population density is low eg in areas of the central parts of Tanzania.

Soil fertility: Fertile soil attracts human settlements for agricultural activities while infertile will discourage human settlement due to its ability to produce enough harvest; hence in areas with fertile land the population density is low.

Political factor: Many people prefer to settle in areas with political stability and peace than in areas where there is political instability.

Employment Opportunities; In areas where employment opportunities are easily available due to presence of many economic activities such as; manufacturing, the population density is high while areas with limited economic activities and employment opportunities, the population density is very low.

Natural Hazards: Such as volcanic eruptions, floods, droughts etc.Those areas with such problem, population density usually tends to be low and vice versa.

Cultural Factors: Some of the tribes tend to live in areas which were left by their ancestors as their heritage and continue to produce on those areas so as to create clans and hence high population density.

Population Census

It the complete process of collecting, comparing and publishing demographic and social[ economic data as regards to people living in a certain country at a certain period of time.

It is a systematic process of collecting, analyzing and publishing of the population data of people living in a certain geographic area at a specific period of time.

In Tanzania the population census exercise is done after every ten (10) years.

After such period of time fundamental changes are expected to take place as regards the population structure and the social economic factors.

Importance of the National Population Census

It is important to the government in the planning process in allocating funds on the provision of social basic services such as education, health etc.

It helps to know the population distribution of people in a certain area and it is on the basis of this that it can be known as to which place are under or over populated

It helps to know the birth and death rate in the country which helps to establish the population growth rate

It helps to determine the dependency ratio in the country by knowing the number of the young and old.

It’s also important for political reasons eg. in determining comparisons over time as regard population size, the birth rate, death rate etc, between countries

Population census data also important for international comparisons over time as regards population size, the birthrate, death rate etc, between countries.

Population census is also important in knowing the population of the country e.g. According to the 2002 population census it was known that, Tanzania has a population size of around 36 million people.

Problems encountered in conducting census in Tanzania LDC at large.

Lack of enough funds: Many LDC, Tanzania inclusive, lack enough funds to carry out a smooth population census exercise. It is upon this that some country at time post pone and other carry out in undesirable manner.

Transport and communication especially in rural areas which results into failure to access some of the areas, delay in reporting data & high transport cost.

Unreliable data on issues such as level of income, education level, age and so on due to the fact that some people at times are not willing to give the right information as regards to those data.

Lack of enough skilled man power which normally results into employing unqualified people for the exercise which normally results into mistakes and errors made.

Lack of enough cooperation from the public for the exercise eg, some refuse to be interviewed others, don’t even allow to access their homes and others give wrong information.

Communication problems. There are some areas where people don’t know Swahili.

At times, the government manipulates the population census data for its own political reasons. As a result of this population data does not reflect what is actually on the ground.

Population Theory

Malthusian Theory and

Optimum population theory

The Malthusian population theory

This theory was developed by Thomas Robert Malthus, a British economist in the 18th century.

In his essay principle of population as it affects the future improvement in society 1798. Malthus examined the relationship between population increase and increase in food production.

The main features of this theory are,

Population increases according to geometric progression i.e. 1,2,3,4,8, whereas the population

Population of a country increases at a higher rate as compared to the increase in production of food stuffs.

If the artificial methods are not adopted to control the population of a country then it becomes double in 25 years time.

If the artificial methods are not adopted to control the population then nature will take the revenge and natural calamities like wars,floods,earth quakes will decrease the population

Assumptions of the theory

Land is fixed i.e. the land size neither increase nor decrease.

The law of diminishing returns operates.

The level of technology is constant.

He also assumed that there is no trade among countries.

Basing on the above assumptions, foods supply will always increase much slower as compared to increase in the population size and therefore there will be a point beyond which the population size will be too much to be fed by the available food and he referred to this point, the population trap. Beyond this point there is likely to be starvation, famine, death and so on.



The area Malthus studied was very small to establish a theory which could be used worldwide.

Malthus did not consider technique progress which can result into increase in food production by applying better farming methods.

He ignored the role of international trade which can help to import more food in order to cover the shortage.

Malthus only looked at people as just consumers without putting into consideration that a high population size will result into more labor supply and hence increase in food supply.

Malthus looked at shortage of food as a result of high population growth rate ignoring other factors such as drought that contributes a lot to food shortage.

Malthus also failed to consider the role of transport & communication which allows food to be transported from areas of surplus to area of shortage

Despite all the above criticism the Malthusian Population Theory is of great application to many LDC’s especially in Africa on the following ground;-

In many LDC’s the population growth rate are very high due to high birth rates but when their food supplies are very low which has resulted into occurrence of starvation.

In some countries which are over populated occurrence of natural calamities such as diseases, floods, earth quakes have reduced the population size.

It is also true that land has fixed supply which is very big limitation in increasing food supply. It is also true that in many LDC’s availability of food has contributed a lot toward increase in birth rate especially in rural areas.

Optimum Population Theory

After modern economists rejected the Malthusian population theory.

Optimum population theory was established. It was stated that the population of a country must be optimum.

Optimum population is that level of population which is most desirable in view of the natural resources of the country. Optimum population is a relative term and it can be determined according to the resources available in the country.

The optimum population theory is more realistic and nearer to reality. This fact makes the Malthusian theory as incompatible these days.

Although, the Malthusian theory has been proved correct in some cases but still it is not a comprehensive or reliable theory.

The invention of new techniques of production and the development of atomic energy has made it possible to increase the population at a greater speed.

The present population trends are not very encouraging but the steps can be taken which can control the population level and increase the production of different commodities to great extent.

Different countries have been very successful to solve this problem to great extent.

Malthusian Theory vs Modern Theory

Malthus focused his attention on food production, where as the modern theory takes in to consideration economic development in all aspects

Malthusian seemed to be thinking of a maximum number for a country which if exceeded about spell misery. According to optimum theory there is no right fixed maximum.

To Malthus famine, war and diseases were indices of overpopulation. But the optimum theory tells us that in the absence of such phenomena there can be over population. It can be shown when per capital income has gone down.

Modern theory is optimistic where the Malthusian theory is pessimistic in outlook. Malthus was haunted by the fear that population would outstrip food supply and spell misery.




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