ABSTRACT
This chapter examines two of the three variables that affect population change: the mortality rate and the fertility rate. It is important to note that life expectancy is measured as a national average value. In countries with chronically high infant mortality rates and where the youths are exposed to risks of diseases and social violence, a high mortality rate of younger generations will push down life expectancy. There are many oil-producing countries in the Middle East and Africa where per-capita income is high, but life expectancy has not improved correspondingly. Life expectancy in the world’s nations has improved remarkably since the 20th century, and there is potential for further extension, especially in Africa. While mortality calculations are based on national populations that already exist, it is the fertility rate that ultimately determines the size of a national population.
