Home Biologist salary How population growth helps, not hurts, the world’s resources and ideas.

How population growth helps, not hurts, the world’s resources and ideas.


With few exceptions, most scholars of antiquity were either hostile to population growth or deeply ambivalent about its potential effects on human well-being. Of course, more people meant bigger armies and more taxpayers, which mattered to the feudal lords of old, but population growth also meant greater pressure on available resources and other calamities.

It was not an irrational prism through which to view population growth. For thousands of years the world has actually been stuck in what has been called a Malthusian trap. The world’s population has fluctuated, rising during times of good harvests and plummeting when food was scarce. According to the US Census Bureau, the world population at the time of Jesus was between 170 and 400 million. Fourteen centuries later it was somewhere between 350 million and 374 million.

In the 18th century, the rapidity of scientific and technological progress enabled certain scholars to envisage population growth with growing optimism. They began to view human life as intrinsically valuable and the attendant problems of population growth as completely solvable. The French economist Nicolas Baudeau, for example, argued that “the productivity of nature and the assiduity of man are without known limits” because production “can increase indefinitely”. Thus, “population and well-being can continue to progress together”.

Other leading intellectuals of the time went so far as to assert that good government is one that leads to the maximization of human population and its welfare. Scottish philosopher David Hume, for example, noted that “where there is the most happiness and virtue and the wisest institutions, there will also be the most people”. The French philosopher Jean-Jacques Rousseau argued that “the government under which…citizens grow and multiply the most is infallibly the best”.

These were, to say the least, revolutionary ideas, and the almost inevitable backlash against them soon arrived. Reverend Thomas Robert Malthus was born in Westcott, England. He studied English, Classics and Mathematics at Cambridge University. Over time, Malthus became fascinated with geometric and arithmetic growth rates. A geometrically increasing value increases in proportion to its current value, such as always doubling (eg, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024). An arithmetic growth rate, on the other hand, increases at a constant rate (1, 2, 3, 4 or 1, 3, 5, 7).

In 1798, Malthus published “Essay on the principle of population”. He argued that “population, when unchecked, increases in a geometric ratio. Subsistence (on the other hand) only increases in an arithmetic ratio. He went on to warn that if “the proportion of births to deaths for some years indicates an increase in numbers far beyond the proportional increased or acquired production (i.e. food) of the country, we can be perfectly certain that unless emigration takes place, deaths will soon exceed births…. If there were no other causes of depopulation, every country would, without doubt, be subject to periodic plagues or famine.

Malthus believed that history validated her theory, which she did. He also insisted that what was true in the past would also be true for all eternity, and it was not to be. Malthus actually lost his main point even before his first book was printed. Between 1700 and 1798, the population of England increased by 62.3%. Relative to income, however, the price of bread fell by 26.6%. In other words, it has become more abundant. While Malthus was shown to be spectacularly wrong, his theory has remained influential among many researchers, including Stanford University biologist Paul Ehrlich.

In 1968, Ehrlich published a book called “The Population Bomb”. It sold 3 million copies, was translated into many languages, and brought Malthusian concerns into the mainstream. It all started with a prediction: “The battle to feed all of humanity is over. In the 1970s, hundreds of millions of people died of hunger despite all the emergency programs launched today. In 1970, Ehrlich appeared on “The Tonight Show.” The show, wrote John Tierney in The New York Times, “received more than 5,000 letters about Ehrlich’s appearance, the first of many on the program. Ehrlich has since been inundated with requests for talks, interviews and opinions.

Ehrlich’s message frightened and scarred generations of Americans, inspiring films such as the 1973 dystopian eco-thriller “Soylent Green.” (The more recent “Avengers: Infinity War” is based on the same premise.) Across the country, University of Maryland economist Julian Simon isn’t convinced. He looked at the numbers and noticed that resource prices were going down instead of up. This implied that resources became more abundant, even as the population grew.

In 1980, Simon bet Ehrlich $1,000 on $200 amounts of five metals: chromium, copper, nickel, tin, and tungsten. The futures contract stipulated that Simon would sell these same quantities of metal to Ehrlich at the same price in 10 years. Since price reflects scarcity, Simon would pay if the increase in population made these metals rarer, but if they became more abundant and therefore cheaper, Ehrlich would pay. Over the next 10 years, all five metals became cheaper, and Ehrlich sent Simon a check for $576.07, representing a 36% drop in inflation-adjusted prices.

Population and well-being can continue to progress together.

Since 1990, some scholars have argued that Simon was lucky. To test this hypothesis, we analyzed the prices of hundreds of commodities, goods and services over two centuries. In our book, “Superabundance: The Story of Population Growth, Innovation, and Human Flourishing on an Infinitely Bountiful Planet,” Gale L. Pouley and I discovered that resources become more abundant as population was increasing. This was especially true when they looked at “prices of time.”

Most people are familiar with the so-called “current” prices, which the buyer sees on supermarket shelves, and the “real” prices, which take inflation into account. What both prices lack is the dollar amount in your wallet. How many times did you hear your grandparents complain that a gallon of gas cost 50 cents and a loaf of bread 5 cents “in the good old days”? “That’s right, grandma and grandpa,” should be your answer, “but what happened to your earnings during your working life?”

Usually, but not always, individual incomes increase at a rate higher than inflation. This is because people tend to become more productive (i.e., they use new knowledge or inventions to generate more value per input, such as an hour of labor, an acre of land, and the amount of capital available) over their lifetime and over time. Just think of the economic output or productivity of a worker with a shovel versus that of a driver of a giant excavator.

While nominal and real prices are measured in dollars and cents, time prices are measured in hours and minutes. To calculate a time price, simply divide the nominal price of a good or service by your nominal hourly income. This tells you how long you have to work to afford something. As long as your nominal hourly income increases at a faster rate than nominal prices, goods and services become more abundant.

Take, for example, an unskilled worker – say a janitor – in the United States. Between 1850 and 2018, the hourly price of rice fell by 98.1%. So the same amount of labor that bought him a pound of rice in 1850 bought him 52.92 pounds in 2018. Instead of a pound of pork, he was able to buy 35.56. His personal “abundance” of cotton increased from 1 to 32.74; wheat from one to 30.79; corn from 1 to 26.04; of wool from one to 24.99; of lamb from one to 3.78; beef from 1 to 3.23, etc. During this time, the population of the United States grew from 23 million to 327 million.

What happened to world prices for time resources? They have fallen by 84% between 1960 and 2018. The abundance of personal resources of the average person on the globe has increased from 1 to 6.27 or 527%. That is, for the same amount of work he could buy one item in the resource basket we looked at, he can now get more than six. During this 58-year period, the world’s population grew from 3 billion to 7.6 billion. It will reach 8 billion by the time you read this article.

More importantly, we also found that personal resource abundance grew at a faster rate than population growth—a relationship we call “overabundance.” On average, each additional human being creates more value than it consumes. This relationship between population growth and abundance is deeply counter-intuitive, but it is true. But, how does all this progress happen?

Committees have no ideas. Algorithms have no ideas. The machines have no ideas, at least not yet. Until now, ideas have always been the product of human intelligence. These ideas lead to inventions, and in turn, market-tested inventions lead to innovations that spur economic growth and higher living standards. But large populations are not enough to sustain the glut – just think of the poverty in China and India before their respective economic reforms. To innovate, people must be allowed to think, speak, publish, associate and disagree. They must be allowed to save, invest, trade and make profits. In a word, they must be free.

Society provides the incentives that encourage or discourage individuals to realize their ideas. Individuals, who do not have the same legal rights and face onerous regulatory burdens, confiscatory taxation or insecure property rights, will be discouraged from turning their ideas into inventions and innovations. Conversely, people who operate under conditions of legal equality, reasonable regulation, moderate taxation and secure property rights will apply their talents for their benefit and, ultimately, that of society.

The possibilities for creating new value are therefore immense. The world is a closed system like a piano is a closed system. The instrument only has 88 keys, but these keys can be played in an almost endless variety of ways. The same is true for our planet. Earth’s atoms may be fixed, but the possible combinations of these atoms are endless. What matters, then, are not the physical limits of our planet, but the human freedom to experiment and reimagine the use of the resources available to us.

Marian L. Tupy is editor-in-chief of HumanProgress.org and senior fellow at the Center for Global Freedom and Prosperity at the Cato Institute. He is co-author of the recently published book “Superabundance: The Story of Population Growth, Innovation and Human Flourishment on an Infinitely Bountiful Planet”.

This story appears in the October issue of Desert Magazine. Learn more about how to subscribe.