Definition of the Malthusian Theory of Population

The Malthusian Theory of Population involves arithmetic food supply growth and exponential population growth. This theory was first published in 1798 in Thomas Robert Malthus’s piece, An Essay on the Principle of Population. Malthus believed that the population could be controlled in order to balance the food supply through positive checks and preventative checks. These checks led to the Malthusian catastrophe. 

Malthusian Theory of Population Explained

Population and Food Supply

According to Thomas Malthus, populations grow in geometric progression. A geometric progression refers to a number sequence in which each term following the first can be found by multiplying the previous one with a common ratio, which is a fixed, non-zero number. For instance, in the sequence 2, 6, 18, 54, 162, the common ratio is 3. 

Malthus also stated that food production increases through arithmetic progression, which is a number sequence with a constant difference between consecutive terms. For example, in the sequence 2, 4, 6, 8, 10, the constant difference is 2. Malthus derived this conclusion from the Law of Diminishing Returns. Since the population grows through geometric progression and the food production increases through arithmetic progression, we can conclude that the population will grow more quickly than the food supply. This will result in a food shortage. 

Population Control

Malthus argued that since the population will be larger than the food supply, many people would then die due to the shortage of food. He theorized that this correction would function through Positive (or Natural) Checks and Preventative Checks. These checks resulted in the Malthusian catastrophe, bringing the population down to a sustainable level.

Positive or Natural Checks

Malthus believed the imbalance between population growth and food supply would be corrected by natural forces, such as earthquakes and floods. He also believed the imbalance would be corrected by human actions like wars and famines. 

Preventative Checks

In addition, Malthus suggested the use of preventative measures to control population growth. These included celibacy, late marriage, and family planning. 

The Malthusian Trap

The Malthusian Trap, also known as the Malthusian Population Trap, refers to the idea that increased food production as a result of advanced agricultural techniques creates higher population levels. These higher population levels then lead to food shortages, as the new population must live on land that was previously used for crops.

Malthus then theorized that even though technological advancement would typically lead to income gains per capita, the gains wouldn’t be achieved because, in practice, the advancement creates population growth. A Malthusian crisis is created as the population exceeds the amount that can be supported by the food supply, and famine and disease will become rampant. Through the Malthusian crisis, the population is decreased to earlier levels. 

In reality, though, population growth has not created the crisis predicted by Malthus. In the following section, we’ll go over the ways in which the Malthusian Trap has been disproven. 

Criticisms of the Malthusian Theory of Population

Population Growth

Malthus’s dire predictions haven’t played out in the real world. For example, in Western Europe, populations have grown, and food production has risen as well due to technological advancements.

Food Production

Food production has seen a dramatic increase over the past century, thanks to multiple technological advancements. In many cases, the food production rate has increased more rapidly than the population growth rate. For instance, in the 1930s United States, a quarter of the population worked in the agricultural sector, and the total GDP was less than $100 billion. But today, less than 2% of the population works in the agricultural sector, and the total GDP is more than $14 trillion. 

Global Trade

Malthus’s theory on the constraints of food production was based on the limited availability of land at that time. But thanks to globalization, we can now trade goods and services for food. This results in a rise in the amount of food that a country can consume.

Calculations

Malthus didn’t provide calculations for the arithmetic growth of food and the geometric growth of populations. Since he came out with his theory, experts have pointed out that the current growth rates are not consistent with the predictions put forth by Malthus.