Malthusianism is a theory that population growth is potentially exponential, according to the Malthusian growth model, while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population decline. This event, called a Malthusian catastrophe (also known as a Malthusian trap, population trap, Malthusian check, Malthusian snatch, Malthusian crisis, point of crisis, or Malthusian crunch) has been predicted to occur if population growth outpaces agricultural production, thereby causing famine or war. According to this theory, poverty and inequality will increase as the price of assets and scarce commodities goes up due to fierce competition for these dwindling resources. This increased level of poverty eventually causes depopulation by decreasing birth rates. If asset prices keep increasing, social unrest would occur, which would likely cause a major war, revolution, or a famine. Societal collapse is an extreme but possible outcome from this process. The theory posits that such a catastrophe would force the population to "correct" back to a lower, more easily sustainable level (quite rapidly, due to the potential severity and unpredictable results of the mitigating factors involved, as compared to the relatively slow time scales and well-understood processes governing unchecked growth or growth affected by preventive checks). Malthusianism has been linked to a variety of political and social movements, but almost always refers to advocates of population control.
These concepts derive from the political and economic thought of the Reverend Thomas Robert Malthus, as laid out in his 1798 writings, An Essay on the Principle of Population. Malthus suggested that while technological advances could increase a society's supply of resources, such as food, and thereby improve the standard of living, the abundance of resources would enable population growth, which would eventually bring the supply of resources for each person back to its original level. Some economists contend that since the Industrial Revolution in the early 19th century, mankind has broken out of the trap. Others argue that the continuation of extreme poverty indicates that the Malthusian trap continues to operate. Others further argue that due to lack of food availability coupled with excessive pollution, developing countries show more evidence of the trap as compared to developed countries. A similar, more modern concept, is that of human overpopulation.
