Malthusian population growth and population pyramids

Economists, demographers, and various social scientists have discussed the issue of population growth. Thomas Malthus, an economist, saw surging population growth as a sign of doom. In $1798$‍, he famously made the prediction that the population would outrun its food supply at a “point of crisis”. He argued that when the means of subsistence (such as food and resources) increases, the population also increases. Population pressures stimulate increases in productivity, but increases in productivity also further stimulate population growth. Population growth is exponential while food supply growth is expected to be arithmetical. Since productivity can never keep up with the potential of population growth for long, there must be strong check on the population to keep it in line with its carrying capacity. However, anti-Malthusians argue that food shortage and starvation are the result of the maldistribution of food and resources rather than overpopulation.

To study population growth dynamics, demographers often utilize population pyramids. Below, by age and sex, are the population pyramids of the US, Mexico, and the world in 1998. Depending on the age structure of the population, some countries have more “population momentum” than others. This concept refers to population growth at the national level that would occur even if levels of childbearing (births) immediately declined. If population momentum is strong for a country, then its population would likely increase rapidly in a short number of years. Just to stay caught up with population growth, a country must double the number of available jobs, housing facilities, food production, water systems, hospitals and other infrastructure. If a country fails to stay even, the standard of living will drop drastically.

Figure 1: Three population pyramids

Data adapted from: Henslin, J. M. (2015). Essentials of sociology: A down-to-earth approach. Pearson.