By the end of the subtopic the learners must be able to:
  1. Identify the factors that affect population growth of a country
  2. Explain how population distribution of a country affects its economic activities
  3. Illustrate the concept of optimum population and how it is linked to the level of resource utilization in the country
  4. Explain the meaning of dependency ration

  • Population is the total number of people who live in a country within a period of time.
  • The size of the population determines the economic activities in a country.
  • Due to the impact of population size on the economy the government should have correct statistics on the composition of the population.
  • Statistics helps to plan on how best to serve people and to use limited resources.
  • The government carries out a national population census in the country on specified periods.
  • In Zimbabwe a national census is carried out every ten years.
  • The last census was done in the year 2012.
  • Population census is the systematic counting of people and the collection of relevant data from them.
  • The size of the population is the number of people who live in a certain area or a country, for example, in Gwanda, Gweru or Plumtree.
  • The population of Zimbabwe has been increasing steadily over the past years.
  • 52% of Zimbabwe’s population is women and population growth rate of 2.3%
  • Population is distributed by age, geographical location, sex and occupation.

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Optimum population

  • It is the number of people who are expected to live in a country so that the country is able to best utilize its natural and man-made resources.
  • This is the population which enables the country to utilize its factors of production in a way that maximizes output per person.
  • At optimum population:
    • The country has sufficient labour force to carry out the production functions in the country.
    • The people in the country are expected to have the best standard of living ever, that is, good sanitation, food, health services, educational facilities as well as recreational equipment.
  • The optimum population is not fixed; it can be affected by the level of technology in the economy.
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Under population

  • It means that the size of the population is small in relation to the available resources in a country.
  • The government will then be forced to come up with measures to increase the labour force in the country.
  • It can employ people from other countries to work in certain areas of the economy.


  • It means that there are more people in the country than the national resources can support.
  • In case of overpopulation, the government and the private sector may need to find ways to improve productivity, for example by improving technology.
  • Overpopulation leads to migration in search for employment opportunities.

Key points

  • Other things being equal, an increase in population above the optimum point leads to overpopulation, whereas a decline in population leads to under population.
  • Under population or over population in the country the income per capital is lower than at the optimum point.
  • When there is under population or overpopulation the standard of living of the people is expected to be lower than at the optimum point level.

Structure of the population

  • This shows how the population is divided in terms of age, gender or area.
  • Census is the counting of people in a country.
  • A census looks at:
    • Age distribution
    • Sex distribution
    • Geographical distribution
    • Occupational distribution
  • Each category has its own characteristics which have significant effects on economic activities of the country.

Population distribution

  • Population distribution refers to how the members of the population are spread out according to their ages, sex, region and race, among others.
  • The way the population of a country is distributed has a great impact on the allocation of resources in an economy.

Age distribution

  • People of different ages make up the population of the country.
  • Age distribution refers to the number of males or females who are at each age group.
  • It is important for the government to know the number of people at various age ranges, as this helps in planning how to use the resources of the country to meet the various needs of the people in the country.
  • All the women and men in the country are put into various age ranges.

Population pyramid

  • A population pyramid is a graph that shows the compositions of males and females arranged by their age ranges.

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  • This pyramid shows that the population is made by many young people.
  • There are fewer old people in this country or place.
  • This type of population pyramid is mainly found in developing countries, such as Zimbabwe, Nigeria, Zambia, etc.
  • This is so because in such countries there is high birth rate and low life expectancy rate.
  • The following is the population pyramid of a developed country.
  • This population pyramid shows a country that has got more middle aged people than those who are below 15 years or those who are 65 years and above.
  • There are lower birth rates; examples include USA, United Kingdom, Canada, etc.
  • The country with such a population pyramid has got a low dependency ratio, since many of the people are within the working population.
  • The country with more people in the age range 15- 65 has a large labour force.
  • High population of aged people leads to a high dependency ratio.
  • This also puts a lot of pressure on the working population as it takes care of the aged people.
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Ageing population

  • This refers to a situation where the number of old and elderly people are increasing in a country, whereas the proportion of children and young adults decrease.
  • An ageing population leads the government and individual households to allocate more resources to meet the needs of these old people.
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Geographical population distribution

  • It relates to how people are spread around various places in the country or the world over.
  • The size of population varies from place to place, for example there are more people in Africa than in Europe.
  • The government needs to understand the number of people who live in each geographical area so that it plans on how best to use the national resources to enhance the welfare of its people.
  • This will also assist the government to distribute its wealth among its provinces or districts.
  • According to the 2012 census results, 33% of Zimbabwe’s population live in the urban centres, whereas 67% lives in the rural areas.
  • The population size in an area changes from time to time due to:
    • People migrating from one place to another in search of employment, education.
    • It can be from rural to urban or to another country.
  • In Zimbabwe most people had to migrate to South Africa to look for employment.
  • As more people move to urban areas the government is forced to allocate more resources to accommodate the increasing population through:
    • Housing land
    • Business premises
    • Roads
    • Other infrastructures like hospitals, clinics.

Occupational distribution of population

  • It relates to how the working population is spread among the different sectors of the economy.
  • The three main sectors of the economy are primary, secondary and tertiary.
  • The primary sector is involved in the extraction of the raw materials like mining, fishing, agriculture, etc.
  • The secondary sector includes the manufacturing and construction industries in an economy.
  • The tertiary sector provides services to industries in a country like banking, insurance, funeral, etc.
  • The distribution of the working population into occupation determines the level of development of a country.
  • Developing countries have a higher proportion of working population in the primary sector and smaller proportion in the tertiary sector.
  • Developed countries have got a higher proportion of employees in the tertiary sector as compared to developing countries.
  • In Zimbabwe there is a large working population in the primary sector, particularly in agriculture.
  • The income per capita is high in countries that have majority of their workforce in the tertiary sector.
  • Countries which have most of their workers in the agricultural and primary industries have low income per capita.

Sex distribution of population

  • Sex distribution refers to the proportion of males and females in the population.
  • It shows the number of females and males who are at various age range of the population.
  • Sex ratio in Zimbabwe states that there are 93 males for every 100 females.

Gender imbalance in a population

  • This is caused by having many people of one sex as compared to another sex.
  • There is a gender imbalance in a population if there are too many males over females or vice versa.
  • A number of causes have been identified for such a situation.

Causes of sex imbalance

  • There is likely to be more females than males if a country has been involved in a war.
  • A war usually leads to the deaths of more males than females.
  • Gender based violence may cause other to relocate to other countries especially females.
  • Men may choose to relocate to other countries in search of employment.
  • Sex selection in some countries, that is, some parents may choose to abort their pregnancies if they expect to bear girls or boys.
  • A typical example is that of China during the one child policy. The parents would abort a female baby as they prefer a baby boy.

Dependency ratio

  • Dependency ratio is the number of economically inactive people who rely on the working population for a living.
  • Dependent population is the number of people who are not able to sustain themselves in any way.
  • It includes all young children who are less than 15 years, students, the sick, the home makers and the old people who are above 65 years.
  • In Zimbabwe many people between the age of 18 and 65 are engaged in production.
  • These people work and produce different products and services which the people consume.
  • When those who are employed earn income they buy goods and services which they need.
Dependency ratio=dependent populationworking population
  • If the dependency ratio in a country is high the standard of living declines since many people have to share their resources with many dependents.
  • If most of the dependents are school children it means that a lot of resources must be channelled to the provision of education.
  • If most of the dependents are aged, a lot of the resources are allocated to the provision of medical facilities.
  • Dependency population may increase because:
    • Many people choose to go on early retirement,
    • The life expectancy of the people in the country has increased due to better medical facilities,
    • Many students are willing to have more years in education now than in previous years.

Population growth

  • It is the increase in the number of people in a country.
  • The population of the world is increasing year after year.
  • Zimbabwe’s population is also increasing.
  • Population size is the total number of people who live in a given area or a country.
  • There are a number of factors that explain population growth.

1. Birth rate

  • This is the main factor that influences the population growth rate of a country.
  • The natural rate of increase of population is the difference between birth rate and death rate.
birth rate=total births total population×1000
  • If the birth rate is greater than the death rate, there is a positive population growth rate in the country.
  • However if the death rate is greater than the birth rate there is a negative growth rate in that country
  • There are very few countries, if any, in the world that experience negative growth rates.
  • Most countries of the world have higher birth rates than death rates leading to population growth.
  • The following factors affect birth rate in a country:

Family planning services

  • The availability of family planning services such as contraception has led to smaller family sizes.
  • Most educated people are now opting for smaller sizes of families than before.

Customs and religion

  • People in certain areas are influenced by their cultures or religious beliefs to avoid the use of birth control measures hence leading to an increase in birth rate.

Living standards

  • The infant mortality (death of children under the age on one year) rate in many countries has gone down because there are improved health facilities in the countries.
  • The hospitals and clinics are now better equipped to deal with diseases that affect children.
  • Sanitation and housing conditions have improved greatly leading to lower infant mortality rate.
  • In the past many children would die during infancy, which led to parents to have many children as a means to compensate for possible child deaths.

Increased female employment

  • Women who work do not want to break their career, so they avoid having many children.

Marriage age

  • Many people these days tend to marry later in life, after they would have worked for a long time.
  • Late marriages reduce the family sizes.
  • In some countries people marry while still young, this leads to a high birth rate in the country.

Economic prosperity of the country

  • In countries where there is high economic prosperity some people may be willing to have children but their life styles can affect their fertility.
  • In developed countries people’s life styles lead them to be obese. Obesity can lead to low fertility rate.
  • Fertility means the ability of the people to bear children.
  • Fertility rate is the average number of children a woman can bear in her life time.
  • If fertility rate is high the population will grow; if fertility rate is low population growth is reduced.

Level of poverty

  • In some countries where there is poverty, parents choose to bear more children with the hope that these children would provide labour for their economic activities such as farming.
  • Some parents believe that if they have many children, these children will look after them when they are old.

Infant mortality

  • If there is a high level of infant deaths in a country, normally the birth rate would be high as parents would expect some of their children to die before they reach adult age.

2. Death rate

  • Death rate refers to the number of people who die compared to every 1000 members of the population in a year.
  • If the life expectancy in the country improves it means that people live longer than before.
  • Increased life expectancy leads to a higher population growth within a certain period.
  • If the number of people who die decrease then there is a lower death rate.

A low death rate in a country leads to high dependency ratio.

Death rate=total deathstotal population×1000

Factors that affect the death rate

  • Availability of health care facilities and services in a country.
  • The level of standard of living in the country.
  • Availability of good sanitation and clean water.
  • Spreading of infectious diseases in the country, such as Ebola and bird flu.
  • Presence and nature of conflicts and crimes in the country,
  • Occurrence of natural disasters in the country, for example earth quake, floods or veld fire.

3. Net migration

  • Migration means the movement of people from one place to the other.
  • The movement of the people from other countries into our country is called immigration.
  • When people move out of the country it is called emigration.
  • Net migration is the difference between immigration and emigration.
  • When the total number of people who leave the country is more than the total number of people who come into the country during a period of time it is called positive net migration.
  • When the number of emigrants is more than that of immigrants, there is negative net migration.
  • The population size of a country increases when there is a positive net migration, whereas the population will decrease if there is negative net migration.

The effects of different population structures on the economy

  • Changes in population size have effects on the economy of the country.
  • Changes that increase the population of labour force will affect the production level in the economy.
  • The reason for this is that labour is one of the factors of production.
  • When there is enough supply of skilled and experienced labour in the country productivity is most likely to increase.
  • An increase in population leads to a higher demand of goods and services in the economy.
  • Therefore, businesses in the country will respond by producing more goods and services to meet the demand level.
  • As the businesses increase production of goods and services more employment is created in the country.

An increase in working population

  • An increase in the working population reduces the dependency ratio.
  • Higher labour force can stimulate economic growth and increase the national output.
  • The standard of living of the people in the country is likely to improve.
  • To further enhance productivity of the labour force training and educational opportunities must exist so that the employees acquire the required knowledge and skills.

A rise in dependency rate

  • An increase in the dependency ratio means that the income received by the workers is spread over many people.
  • The government will be forced to allocate more resources to the production of social services such as schools, hospitals and housing.
  • The production of more consumer goods on the expense of capital goods reduces the rate of economic growth.

Increase in ageing population

  • More resources will be allocated to the production of consumer products that cater for the need of the aged.
  • The ageing population is composed of all people who are 65 years and more.
  • The main needs of the ageing population include good health care, old people’s homes and enough supply of food and clothes.
  • There is more government and household spending on consumer goods the economic growth rate of the country is reduced.