Question

Explain CLEARLY a minimum of 2 theories that the Thomas Robert Malthus developed that had significance to the field of economics.

Answer 1

First of all, we quickly get to know about Thomas Malthus so that there will be no problem in understanding their theory.

Thomas Robert Malthus was a famous 18th-century British economist known for the population growth philosophies outlined in his 1798 book "An Essay on the Principle of Population." In it, Malthus theorized that populations would continue expanding until growth is stopped or reversed by disease, famine, war, or calamity. He is also known for developing an exponential formula used to forecast population growth, which is currently known as the Malthusian growth model.
In the 18th and early 19th centuries, philosophers broadly believed that humanity would continue growing and tilting toward utopianism. Malthus countered this belief, arguing that segments of the general population have always been invariably poor and miserable, which effectively slowed population growth.

After observing conditions in England in the early 1800s, Malthus penned "An Inquiry into the Nature and Progress of Rent" (1815) and "Principles of Political Economy" (1820), in which he argued that the available farmland was insufficient to feed the increasing world population. Malthus specifically stated that the human population increases geometrically, while food production increases arithmetically. Under this paradigm, humans would eventually be unable to produce enough food to sustain themselves.
This theory was criticized by economists and ultimately disproved. Even as the human population continues to increase, technological developments and migration have ensured that the percentage of people living below the poverty line continues to decline. In addition, global interconnectedness stimulates the flow of aid from food-rich nations to developing regions.

In India, which boasts the world's second-biggest population, the Green Revolution in the state of Punjab helped feed its growing population. In western economies like Germany, which was battered during World War II, population increases did not hamper development.

Malthus argued that two types of checks hold population within resource limits: positive checks, which raise the death rate; and preventive ones, which lower the birth rate. The positive checks include hunger, disease and war; the preventive checks: birth control, postponement of marriage and celibacy.

Known for his work on population growth, Thomas Robert Malthus argued that, left unchecked, a population will outgrow its resources. He discussed two ways to 'check' a population: preventive checks, like the moral restraint of postponing marriage, or positive checks, like famine, disease and warfare.

Famous naturalist Charles Darwin partially based his natural selection theory on Malthus' analysis of population growth. Furthermore, Malthus' views enjoyed a resurgence in the 20th century, with the advent of Keynesian economics.

The Malthusian Theory of Population is a theory of exponential population growth and arithmetic food supply growth. Thomas Robert Malthus, an English cleric, and scholar, published this theory in his 1798 writings, An Essay on the Principle of Population.

He believed that through preventative checks and positive checks, the population would be controlled to balance the food supply with the population level. These checks would lead to the Malthusian catastrophe.

Thomas Malthus theorized that populations grew in geometric progression. A geometric progression is a sequence of numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the common ratio. For example, in the sequence 2, 10, 50, 250, 1250, the common ratio is 5.

Additionally, he stated that food production increases in arithmetic progression. An arithmetic progression is a sequence of numbers such that the difference between the consecutive terms is constant. For example, in series 2, 5, 8, 11, 14, 17, the common difference of 3. He derived this conclusion due to the Law of Diminishing Returns.

From this, we can conclude that populations will grow faster than the supply of food. This exponential population growth will lead to a shortage of food.

Malthus then argued that because there will be a higher population than the availability of food, many people will die from the shortage of food. He theorized that this correction would take place in the form of Positive Checks (or Natural Checks) and Preventative Checks. These checks would lead to the Malthusian catastrophe, which would bring the population level back to a ‘sustainable level.

He believed that natural forces would correct the imbalance between food supply and population growth in the form of natural disasters such as floods and earthquakes and human-made actions such as wars and famines.
To correct the imbalance, Malthus also suggested using preventative measures to control the growth of the population. These measures include family planning, late marriages, and celibacy.

The Malthusian Trap (or “Malthusian Population Trap”) is the idea that higher levels of food production created by more advanced agricultural techniques create higher population levels, which then lead to food shortages because the higher population needs to live on land that would have previously used to grow crops.

Even as technological advancement would normally lead to per capita income gains, theorizes Malthus, these gains are not achieved because in practice the advancement also creates population growth. Once the population exceeds what food supplies can support, this supposedly creates a Malthusian crisis with widespread famine as well as rampant disease. This ends up decreasing the population to earlier levels.

The reality, however, has been that population growth has not itself created the crisis that Malthus predicted. We will discuss the ways in which the Malthusian Trap has been disproven in the following section.