The first economist to suggest there were limits to how many inhabitants a country could support was Thomas Malthus (1766 – 1834), in: An Essay on the Principle of Population (1798). Malthus believed that each country had a “carrying capacity,” a maximum number of people it can support. When the population is above its carrying capacity, it is full.
Carrying capacity is based on environmental factors, such as the amount of food resources that can be grown on land or harvested from the sea. If Malthus were alive today, he would point out there is a fixed amount of oil in the Earth and a fixed amount of farmland to grow crops. Sooner or later the oil will run out, and if population grows without bound, there will not be enough food to feed everyone.
Malthus predicted that if a country rises above its carrying capacity, the result would be: disease, famine and war. These would reduce the population to a sustainable level. In simpler words: The population in a country cannot grow beyond a specified point, that is constrained by death. This conclusion is one of the reasons people began to call economics the dismal science.
Jared Diamond, in Collapse: How Societies Choose to Fail or Succeed (2005), examines a range of past societies in an attempt to identify why they either collapsed or continued to thrive and considers what contemporary societies can learn from these historical examples. He argues against cultural explanations, but focuses on ecology. Among the societies mentioned in the book are the Norse and Inuit of Greenland, the Maya, the Anasazi, the indigenous people of Rapa Nui = Easter Island, Japan, Haiti, the Dominican Republic, and Montana. Numerous times in history, excessive population growth in terms of resources led to environmental damage that destroyed that society. The damage was precipitated by people being forced to move onto marginal or unsafe lands.
Many other economists hold the opposite view and argue population growth fosters economic progress, which means an ever-growing amount of goods and services.
Julian Simon (1932 – 1998) studied economics in terms of population, natural resources and immigration. He is known for his cornucopian views = nature is abundant, and as a critic of Malthus. Simon focused on the lasting economic benefits of continuous population growth, despite finite = limited physical resources. Human ingenuity creates substitutes and technological progress. A growing population is advantageous because it allows more researchers, inventors, thinkers, writers and creative people contributing to economic growth. The Ultimate Resource (1981) is a criticism of what was then the conventional wisdom on resource scarcity
These kinds of ideas were expanded by Michael Kremer (1964 – ), by suggesting it takes a critical mass of people to develop advanced societies. He contends that societies with high population densities are the most dynamic and most productive. He was awarded the 2019 Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel = Sveriges riksbanks pris i ekonomisk vetenskap till Alfred Nobels minne (Swedish), commonly referred to as the Nobel Prize in Economics, along with Esther Duflo (1972 – ) and Abhijit Banerjee (1961 – ) for their experimental approach to alleviating global poverty. Their work popularizing the use of randomized controlled trials (RCT) in development economics.
Among his earliest contributions was the O-ring theory of economic development, named for the Space Shuttle Challenger disaster, in which a cascading failure was caused by the malfunctioning of a single small component. Complex products often require completing many steps correctly for the final product to have any value. This work was inspired by his time in Kenya, when he organized a training session for WorldTeach volunteers, but forgot to purchase toilet paper for the event.
Kremer’s Nobel lecture, Experimentation, Innovation, and Economics (2019) provided an overview of the experimental revolution in development economics, arguing that RCTs can be a powerful tool for influencing public policy and promoting innovation. To do this, he draws on many examples of his own work, including that on deworming (reducing school absenteeism by 25% and increasing adult incomes significantly) and fertilizer usage (Third-world farmers may procrastinate or postponing fertilizer purchases until later periods, when they may be too impatient to purchase fertilizer. Consistent with the model. Many farmers in Western Kenya fail to take advantage of apparently profitable fertilizer investments, but invest in response to small, time-limited discounts = free delivery, just after harvest. This policy can yield higher benefits than heavy subsidies).
The reason why large populations are good is straightforward. Few ideas come from people who are isolated. Numerous people who are together in close proximity produce more ideas because they learn from each other and compete. Proponents of population growth point out most of the new ideas and products come from cities like New York City, London and Paris. The places brimming with ideas are dense, crowded major urban centers teeming with people.
The United States of America has not reached its carrying capacity. Despite this, President Donald Trump has pledged to deport millions of immigrants, which could upend American farming economies.
Immigrants make up about two-thirds of the nation’s crop farmworkers. About 40% of them are illegal immigrants. Agricultural industries such as meatpacking, dairy farms, poultry and livestock rely heavily on immigrants. Many agricultural employers can not find enough laborers. Employers have a hard time hiring enough farm laborers because such workers generally are paid low wages for arduous work. The H-2A visas program can provide workers for seasonal work, usually 6–10 months. However, these can be extended for up to three years before a worker must return to their home country. Employers must pay H-2A workers a state-specific minimum wage and provide no-cost transportation and housing. The number of H-2A positions has surged from just over 48 000 in 2005 to more than 378 000 in 2023. Agricultural employers that operate year-round, such as poultry, dairy and livestock producers, can not use the seasonal visa to fill gap. Farmers may also employ foreign nationals who have temporary protected status under a 1990 law that allows immigrants to remain if the U.S. has determined their home countries are unsafe because of violence or other reasons. There are about 1.2 million people in the U.S. under the program or eligible for it, from countries including El Salvador, Ethiopia, Haiti, Honduras, Lebanon, and Ukraine. Many have been here for decades. However, the current administration has threatened to end this program. Immigration advocates want a pathway for H-2A workers to gain permanent legal status, and agricultural trade organizations are pushing for an expansion of the H-2A program to include year-round operations.