The Malthusian trap or Malthusian check refers to the theory that as the human population grows there is increasing pressure on earth’s resources, which in turn acts as a check on the further rise in population. It is named after English economist Thomas Malthus who elaborated on the concept in his 1798 book An Essay on the Principle of Population, which quite famously inspired Charles Darwin. In his book, Malthus argued that while rise in food production in a country can lead to improved living standards for the general population, the benefit is likely to be temporary. This is because, Malthus argued, increasing availability of food would encourage people to have more kids since they could afford to feed them now, thus leading to a rise in the total population and a drop in per capita income levels. Malthus, in other words, believed that there was an inverse relationship between human population and living standards with rising population leading to lower living standards.
Malthus’ idea has often been cited by modern environmentalists and other social scientists who believe that rising human population puts unsustainable pressure on earth’s resources. The per capita income of countries remained fairly low and largely stable for many centuries until the modern age. In the pre-modern age, whenever there was a rise in food production due to whatever reason, this caused per capita income to rise for a while as long as population levels remained stable. However, the population of the country increased quite quickly which ensured that per capita income returned to its historical trend. Whenever food production dropped on the other hand, there was famine which caused the death of a large number of people. The drop in human population continued until the country’s per capita income rose to subsistence levels. Either way, resource constraints kept a check on human population.
The industrial revolution that happened in the 18th and 19th centuries is seen as a landmark event that broke the historical relationship between human population and living standards. It witnessed the rising use of man-made technology, which made sure that human beings could produce more output in the form of goods and services for each unit of the earth’s resource that they exploited. In other words, human productivity rose massively as a result of the rise of technology.
Critics of the Malthusian trap believe that the industrial revolution decisively refuted Malthus as human population levels and living standards have risen in tandem ever since the event. In other words, according to critics, there may be no strict inverse correlation between population growth and the living standards of people. As long as human beings can find ways to use earth’s resources more efficiently, their population can grow without compromising their living standards even in the long-term. In fact, some argue that as human population rises, the chances of breakthrough innovations happening rise manifold as there would be more human minds working on solving humanity’s problems.
The Malthusian trap was at the core of the Simon-Ehrlich wager, which was a bet placed in 1980 between American business professor Julian L. Simon and American ecologist Paul R. Ehrlich. While Ehrlich, like Malthus, argued that there are natural limits to economic growth, Simon disagreed with him. Simon argued that private property rights and the price mechanism in a market economy offered tremendous incentives for people to use scarce resources carefully and to come up with innovations. This, Simon argued, ensured that living standards could rise along with increasing population levels.