What causes population to increase or decrease?

Demographers – population specialists – have concluded that the total population of the whole world will reach 7 billion on October 30, 2011 and will continue to increase thereafter.

There has been confusion about why the global population is increasing. What is causing an increase is not a rise in fertility but a fall in mortality. In other words, mortality is falling faster than fertility.

There is worry that if the global population continues to grow sooner or later the demand for goods and services will exceed their supply, causing all sorts of problems including famines and war over scarce resources. The relatively easy solution is to stop or reduce drastically population increase. This can be achieved in two ways – increase mortality and/or reduce fertility. Since it is morally wrong to recommend mortality increase, the only alternative is fertility reduction to 2.1 children per couple.

At continental, regional or national levels population increase or decrease is due to the difference between fertility and mortality (natural increase or decrease) and the difference between in-migrants and out-migrants (positive or negative migration). For example, when fertility exceeds mortality and in-migrants exceed out-migrants the population will increase. On the other hand when fertility is lower than mortality and in-migrants are fewer than out-migrants the population will decrease.

A country that has a higher fertility than mortality and more in-migrants than out-migrants and needs to reduce population growth it has to decide whether it wants to reduce fertility or reduce in-migrants or do both.

Fertility rate has remained higher in Africa especially in Sub-Saharan Africa than in any other continent. Therefore to reduce global population growth, fertility in Africa should come down. In order to do so successfully, we need first and foremost to understand why fertility has remained high, albeit it is going down slowly. A combination of the following factors is responsible for rapid natural population increase:

1. Absolute poverty has remained very high. Poor people experience a high mortality rate because of malnutrition, communicable diseases and conflicts etc. In order to survive as a family, community, nation or religion they produce many children. The subsistence nature of their existence (collecting water, gathering fuel wood, attending to livestock or siblings, gardening, cooking and attending to the sick etc) requires many hands. They also need support in old age because they do not have pension.

2. Lack of entertainment such as television or radio programs because they cannot afford or there is no electricity or kerosene to light the house and keep them awake until late in the night, couples go to bed early where they find entertainment that does not require light. And the outcome is a new baby. This has happened even in developed societies when light went out forcing couples to go to bed early.

3. Girls drop out of school early and are forced into early extramarital pregnancy or early marriage. Once married culture requires that children are produced quickly or questions will be asked whether the couple is normal or not. And if only girls are produced couples are subjected to pressure to continue producing until boys are born, ending up with many children.

4. Lack of women empowerment denies them the ability to manage their reproductive behavior. In many African societies it is men that determine the size of the family. If a wife refuses to comply the punishment can be severe.

5. The use of contraception has experienced constraints – some of them very serious. Either contraceptives are not available, or they are expensive or they cause severe side effects such as loss of sexual interest forcing many to drop out of birth control programs.

Therefore in order to bring down fertility considerably in Africa the above constraints must be addressed concurrently.

Addressing the question of excess in-migration over out-migration or vice-versa is a political issue of fixing disincentives or incentives.

At the global level every effort needs to be made by all to understand the causes of high fertility rate and implement pragmatic location-specific programs especially in Sub-Saharan Africa. A one-size-fits-all solution won’t work. And we should avoid pushing communities that are not ready because that effort – however sincere – can be counterproductive.