Birth Rate or fertility rate is the number of births per 1000 of the population. The birth rate is a measure of fertility.

The physiological capacity of a woman to conceive and give birth to a child, regardless of whether it is a live birth or a stillbirth, is called fecundity.

Lack of fecundity is called infecundity or sterility.

Infertility, on the other hand, refers to the inability of a woman to bear a child and this includes those who cannot give live birth to a live baby. Infertility can be primary or secondary.

Primary infertility is also referred to as involuntary childlessness.

Secondary infertility can be involuntary. For instance, a woman has had two children and is now unable to have more due to biological or health factors.

It is called secondary since it is caused by a second factor after the previous births.

factors affecting birth rate

family planning

There are various family planning programmes which are helping people to have a fewer number of children.

Mainly these programmes educate women on the advantages of having fewer children.

These programmes help to reduce birth rates.

The most targeted areas in Zimbabwe are the communal areas where women have since been taught about the importance of family planning.

religious beliefs

Did you know that some religions do not allow the use of contraceptives (family planning pills, condoms, and other methods of birth control.) and abortion?

They believe that children are a gift from God so people should not worry about having many children.

Most white garment churches encourage their members to marry and have more children.

Some even encourage their members not to worry if they happen to lose a child as they believe that God will give them another child.

need of male child

In most African societies it is very important to have a male child as he will bear the family name.

All the wealth is supposed to be left in his name upon the death of his father. Wealth and the family name are supposed to be passed down from generation to generation.

So, there is a need for a male child.

average age of marriage

People who get married early tend to have quite a number of children thereby increasing birth rates.

Children get married at a tender age especially girls usually between the ages of 12 and 18 years.

This usually happens when a girl gets impregnated by an older man who would have promised.

With a lack of education, the young girls would have more children.

children as the source of labour and security

Having a child is more important in most societies as children are seen as a source of labour and security.

When we say labour, we mean to say that children are there to help in the fields and do most of the household chores.

So, if a family has quite a number of children then it means all the work will be easy to manage with no time.

Security means that parents have children that will take care of them in their old ages and also provide for their needs.

symbol of greatness

Some people believe that having children is a symbol of greatness.

This means that having children is a great achievement and other people will respect and honour you.

The patriarchal societies of Africa consider having more children as a symbol of greatness.

Respect is earned with the number of children a man has.

This, therefore, leads men to have more wives in order to have more children.

level of freedom of women

natalistic policies

develpment of secondary and tertiary economy

level of education

cost of living

infant mortality



The following are Factors favoring high population growth rate in Africa:

  • Limited use of family planning methods.
  • Many people don’t use family planning methods that’s why end up with many children. This leads to high population growth rate. 
  • Decrease in death rate: There is improvement in the general levels of living, improvement in level of education of people, and improvement in the health services with increase in the number of hospitals, dispensaries and health centers, increase on the number of Doctors and nurses and other health personnel hence decrease in death rate leading to rapid growth of population. 
  • Old-age insurance: Children are considered as insurance for a good life in old ages by their parents, for that they produce more children in order to insure themselves.  

  • High infant mortality rate: Parents produce many children in Africa because of not being sure of the number of children who can survive. To avoid unwanted surprises they produce more, some die and other survive.  
  • Cultural believes for large families: Children are sources of prestige in some societies. Many people produce many children for prestigious reasons.  
  • Early marriage: Women marry at a younger age leading to a longer fertility period and more children are produced leading to rapid growth of population.
  • Religion. Some religions preach to people not to use family planning methods to avoid unwanted pregnancies. Not using family planning results into unwanted pregnancies that lead to rapid growth of population.

causes of high death rate in Africa:

  • Insufficient health facilities like hospitals, health centers and dispensaries with enough care
  • There is rapid increase in population but social services and infrastructures have not increased to match the population growth
  • Political instability and insecurity. Many countries of Africa are engaged into war and insecurity is common in those countries hence loss of lives which lead to decrease on the number of population. Example of some countries of Africa includes Sudan, DRCongo, Maghreb, etc.
  • Low levels of Immunization. Children get infected with infant killer diseases leading to increase in the death rate of young children.
  • Poverty, Many people die because cannot afford to buy requirements of life like drugs and food. The cost of life is high than the revenue of many African people living under poverty.

  • Ignorance. Lack of enough information on health care like reproductive health that leads to death of many people.



Population change refers to the difference between the size population at the beginning and at the end of a period.

It can refer to the growth or decline in population.

Population change can also be described as population growth.

This is the increase (positive growth) or decrease (negative growth) in the number of people.

Change in the population is caused by birth, death, and migration.


The factors influencing population change include the birth rate, death rate, and migration. These influence population change negatively and positively.


A high birth rate coupled with a low death rate results in a positive change in population.

This translates into an increase in population. A high birth rate is caused by high fertility and fecundity within a population. Fertility is defined as the ability to conceive or to reproduce.

Fecundity refers to the ability to give birth to many children’s i.e. high fertility. The fertility rate is expressed as a ratio of live birth in an area to the population of that area.

For example, according to the United Nations estimates for 1995  – 2000, the total fertility for Tanzania was 5.5 children per woman aged between 15 and 49 years.

This is the average number of children that women of child-bearing age will have in their lifetime.

The factors influencing fertility include the level of education of the women, urbanization, career prospects, and birth control measures.

These factors tend to influence the fertility rate.

The high fertility rate in East Africa is attributed to improved nutrition, improved health services, and the weakening of the traditional customs like a prolonged period of breastfeeding and sexual abstinence after birth.

The Crude Birth Rate (CBR)

The crude birth rate is estimated rate of births in a year.

It is not a precise figure because the values for the total population that are used for the calculation are an estimated by the middle of the year.

It is obtained by dividing the total number of birth recorded in the year by the estimated total population by the mid-year and multiplying the fraction by 1,000.

The formula would be the Total number of births in the year x 1,000 Total population (mid-year estimates) Tanzania crude birth rate during the period 1995 to 2000 was 40.2 annual live births per 1000 persons.


This factor is sometimes expressed as mortality and it refers to the number of deaths within a given population.

There are three (3) types of death rates. Infant Mortality Rate. Is the number of deaths in the first year of life per one thousand live births.

Child Mortality Rate. Is the number of deaths of children aged between 1 and 5 years per one thousand live births.

Adult Mortality Rate. Refers to the number of adults dying per one thousand of the total population. Mortality is significant in that it results in a reduction of population numbers. It also affects the population structure.

A high death rate of a particular sex or age has a negative bearing on population growth.

Large-scale mortality may be caused by an outbreak of war, famine, disease epidemic or natural disasters such as floods, earthquakes, and volcanic eruptions.

The deaths of a large number of youths and men who are of child-bearing age reduce the number of people involved in child-bearing. The Crude Death Rate (CDR)

The crude death rate is the estimated rate of deaths against an estimated total population by the middle of the year in question.

It is calculated in the same way as the crude birth rate, Thus: Total number of deaths rate in the year x 1000 Total population (mid-year estimate)

The crude death rate is also expressed as the number of deaths per one thousand people.

From the United Nations statistics, Tanzania’s crude death rate from 1995 to 2000 was 12.9 annual death per 1,000 persons.

The reason why they use the term “Crude” is that other characteristics such as age, sex, and composition within a population are ignored.

The natural population growth is obtained by subtracting the CDR from the CBR.

It can be expressed as percentages as

CBR-CDR  X 100 1000 From the 2002 population census conducted in Tanzania, the annual growth rate was found to be 2.9% for the period between 1988 and 2002 (i.e intercensal period).


Migration is the movement of people from one place or region to another which results in a change of residence.

It may be temporary or permanent. Migration may involve immigration where people come into a new area. Those people are referred to as immigrants.

It may also involve emigration where people leave their native land for another land. These people are called emigrants. Migration across countries’ borders is called International Migration.

Migration across the boundary within a country is called Internal Migration. Such migration influences population change on both sides (Origin and Destination) which are affected positively or negatively.

Emigration of a large number of people from their native land results in a reduction of population.

In Africa, an exodus of people from their native countries has largely been attributed to civil wars.

Large numbers of refugees flock to neighboring countries result in an increase in population in the host countries.

Tanzania has been host to many refugees from Rwanda, Burundi, Uganda, the Democratic Republic of Congo and even Somalia Migration of these refugees has resulted in a decrease in population in their native countries.

Some of the refugees may even opt to stay permanently in their host countries and some even change their citizenship.

The populations of refugees also grow through children born among them within the host countries. All these result in positive change in population.


There are two (2) types of migration which include internal migration and external (International) migration.

These types of migration can be in a form of permanent, temporary, voluntary, or involuntary.


This is a movement of people within a country. It can be temporary or long-term. It may be voluntary or forced.

This type of migration goes on all the time and many governments do not attempt to control it.

The reasons for this type of migration are varied. They include searching for jobs, settlement, seeking safer areas, or improvement of people’s lives.

There are those who move to parts of countries where the climate is more favorable. There are four (4) forms of internal migration

  • Rural to Urban migration. In this form, people move from rural areas to towns. People migrate in search of jobs, better social amenities or education, some move to avoid wide spread of unemployment in the rural areas or work on farms.
  • Rural to rural migration. In this form, people move from one rural area to another. Some people move into plantations for employment in the large farms. There are those who moved into new settlement and do farming.

Nomadic pastoralists migrate in search of water and pasture for their animals.

  • Urban to rural migration. Some migrants who moved to towns in search of jobs move back to rural areas to settle because they now have capital to invest in the rural areas.
  • Urban to urban migration. Are migrants who may move from one town to another. This may in search of better employment or business opportunities.


External migration is also known as international, interstate, or inter-regional migration. It is the movement of people from their own countries to other countries.

The people involved are referred to as in their original countries, emigrants, and as Immigrants in their destination countries. Migration may be voluntary as in the case where people go for further studies, employment, or settlement or it may be forced as in the case of refugees.

This migration can be temporary or permanent. For example, International tourists are temporary migrants.