Which of the following statements best explains why parts of southern Africa are not experiencing the same rate of population growth as others?
A.
Fewer children are being born in southern Africa.
B.
More people are migrating to Europe and the United States from southern Africa.
C.
Many people are dying young in southern Africa due to the AIDS virus.
D.
More people are single in southern Africa than elsewhere on the continent.
Answers
Sub-replacement fertility is a total fertility rate (TFR) that (if sustained) leads to each new generation being less populous than the older, previous one in a given area. In developed countries sub-replacement fertility is any rate below approximately 2.1 children born per woman, but the threshold can be as high as 3.4 in some developing countries because of higher mortality rates.[1] Taken globally, the total fertility rate at replacement was 2.33 children per woman in 2003.[1] This can be "translated" as 2 children per woman to replace the parents, plus a "third of a child" to make up for the higher probability of boys born and mortality prior to the end of their fertile life.[a]
Replacement level fertility in terms of the net reproduction rate (NRR) is exactly one, because the NRR takes both mortality rates and sex ratios at birth into account.
As of 2010, about 48% (3.3 billion people) of the world population lives in nations with sub-replacement fertility.[2] Nonetheless most of these countries still have growing populations due to immigration, population momentum and increase of the life expectancy. This includes most nations of Europe, Canada, Australia, Brazil, Russia, Iran, Tunisia, China, the United States and many others. In 2015, all European Union countries had a sub-replacement fertility rate, ranging from a low of 1.31 in Portugal to a high of 1.96 in France.[3] The countries or areas that have the lowest fertility are in developed parts of East and Southeast Asia: Singapore, Macau, Taiwan, Hong Kong and South Korea.[4] Only a few countries have had, for the time being, sufficiently sustained sub-replacement fertility (sometimes combined with other population factors like higher emigration than immigration) to have population decline, such as Japan, Germany, Lithuania, and Ukraine. As of 2016, the total fertility rate varied from 0.82 in Singapore to 6.62 in Niger.[4]