Population Growth: What is the total fertility rate of a country?
This is installment one of a series of articles that explain what drives the population growth of a country.
This article will explain what the fertility rate is, what drives the fertility rate and how it is linked to population growth.
The next artic instalment will look at the definition of birth rate and the difference between the total fertility rate and total (crude) birth rate - two concepts that are often mixed up.
Definition of fertility rate
Rather than use the technical and rather complex definition offered by official organizations, I offer a much simpler definition of what the total fertility rate is:
The total number of children born per woman (in a specific country).
Total fertility rate is calculated by dividing the total number of births in a year by total number of women in fertile age (e.g. 15–49) in a given population.
The fertility rate, therefore, depends on many aspects, but most importantly on the following:
- Socio-cultural: Perhaps the most accepted driver of fertility rate in the social and cultural expectations in a country. As you can see in the graph below, third world and developing countries report much higher fertility rates than developed countries (for example, Nigeria reported 6.9 births per woman vs 1.3 for Spain 2018). One reason is the higher use of contraceptive methods (e.g. preservatives) in developed countries, another is the social and cultural expectations around having more children in third world countries.
2. Biological: It is well documented how the ability of women and men to get pregnant can be affected by their age, weight, or genealogical predisposition.
3. (Bad) Habits: It is also well accepted how certain habits may impact fertility, including smoking, drinking, lack of exercise, or drug abuse among others.
4. Environmental: While there is no definitive answer to this, it is believed that certain products or materials that contain specific chemicals may cause miscarriages or affect pregnancy in other ways.
5. Political: The best example is China’s “one-child policy”, introduced in 1979 with the objective of slowing the population boom that took place in previous decades.
In conclusion, the fertility rate is not an element of population growth, but it is rather a combination of factors that limit or expand the ability of a woman to give birth.
I hope this provides an understanding of what the fertility rate is, please look out for my next!
