In this chapter I will analyze demographic trends globally, as well as trends in different parts of the world, specifically focusing on developed countries, middle-income countries, and developing countries.
Prior to the Industrial Revolution, all countries had a slow population growth that was coupled with high mortality and high birth rates. Because, in pre-industrial societies, the infant mortality rate was high and life expectancy was very low, parents needed to produce as many offspring as possible to make sure that at least one child would reach adulthood.
Let us define some commonly used terms. The birth rate is the number of births per 1,000 people, and the (total) fertility rate is the average number of children per woman, measured by adding up the number of children per woman in each age group at a given time in a country or region.
Over the last 200 years, as a result of the Industrial and Technological Revolutions, the world economy has grown tremendously. Average per capita income grew from just a few hundred dollars to a few thousand dollars globally. As people became wealthier, they had more resources, which in turn enabled them to raise healthy offspring. Advances in medicine and health also resulted in a plummeting infant mortality rate. As a result, life expectancy increased and the world's population grew very rapidly. Although it took some time, people gradually adjusted to the new reality, realizing that, with the lower ...