Books That Shook the Business World: An Essay on the Principle of Population by Thomas Robert Malthus

Malthus thought that overpopulation was unsustainable and risked societal collapse. One of humanity’s greatest achievements was proving him wrong.

Thomas Robert Malthus is remembered for the gloomiest theory proposed in just about any discipline. The story begins in 1793, when the English journalist and philosopher William Godwin published a book called An Enquiry Concerning Political Justice. It predicted a utopian future and became a classic of philosophical anarchism.

One of its admirers was a wealthy landowner named Daniel Malthus. He debated its merits with his adult son, Thomas, a clergyman and Cambridge scholar. Few family debates end as gainfully. Thomas wrote down his counterargument, which was published in 1798 as An Essay on the Principle of Population.

Welcome to our new series on key titles that have helped shape business and the economy – as suggested by Conversation writers. We have avoided the Marxes and Smiths, since you’ll know plenty about them already. The series covers everything from demographics to cutting-edge tech, so stand by for some ideal holiday reading.

The core thesis was that any improvements in food production would quickly be overwhelmed by population growth. Advances made today would just increase the population tomorrow, meaning more mouths to feed. Since the amount of agricultural land was finite, population growth would inevitably drag most people back to bare subsistence level. Humanity was thus caught in an eternal trap.

While the data available to Malthus was severely limited, the historical record seemed to be on his side. Centuries had passed in Britain without any perceptible increase in living standards. Despite an uptick in the late 18th century, output per person was still only about US$3,000 (£2,337) a year in today’s money.

UK GDP per capita in US$ real terms (AD1 to present day)

Big predictions have a habit of arriving just before they are resoundingly debunked, which of course is what happened to Malthus. The “uptick” was the beginning of the industrial revolution, which led to eye-popping improvements in living standards.

For the first time in history, humanity began a sustained run of technological innovation that far outpaced population growth. Educational, social and technological advances then helped people to limit their fertility, further unshackling them from the trap.

By 2018, output per person in Britain had increased twenty-fold. Human welfare has improved more in the past two centuries than it did in the previous 200,000 years: at first, in just a few countries, but increasingly everywhere. In 1900, output in sub-Saharan Africa had barely increased since Malthus published his essay. It has since more than quadrupled.

Mitigating Malthus

If Malthus’ predictions of eternal penury were wrong, why celebrate him? Many writers make this point, and Malthus is often portrayed as both misguided and misanthropic. Notably he criticised the English poor laws, arguing that giving aid to those who were struggling only encouraged them to have more children, thus aggravating the central problem of overpopulation. The same logic has been used to justify the political arguments of people of dubious moral standing ever since.

At a purely intellectual level, however, this is a rather unfair reason to dismiss somebody who concisely explained the human condition as it had existed throughout history.

Few classics of economic thought could be considered great reads. Malthus’ friend, David Ricardo, is regarded as one of the best economic theorists ever, but his writings are interminable. This is what makes reading An Essay on the Principles of Population so surprising: it is beautifully written, overflowing with humanity, and a genuine page-turner.

Malthus’ logic led him to dark conclusions, but not because he only cared about the elite; in fact, he was gloomy precisely because he was concerned about the lot of everyone else:

In estimating the happiness of a savage nation, we must not fix our eyes only on the warrior in the prime of life: he is one of a hundred: he is the gentleman, the man of fortune, the chances have been in his favour …

The true points of comparison between two nations seem to be the ranks in each which appear nearest to answer to each other. And in this view, I should compare the warriors in the prime of life with the gentlemen, and the women, children, and aged, with the lower classes of the community in civilised states.

One would expect an intellectually minded economic theorist and churchman like Malthus to be emotionally withdrawn. But he was startlingly rounded and open, far more empathetic than the popular caricature:

Perhaps there is scarcely a man who has once experienced the genuine delight of virtuous love, however great his intellectual pleasure may have been, that does not look back to the period as the sunny spot in his whole life, where his imagination loves to bask, which he recollects and contemplates with the fondest regrets, and which he would most wish to live over again.

Today’s perspective

Malthusianism has cast a long shadow in the popular imagination (fans of the Avengers movies will recognise the supervillain Thanos as an unabashed Malthusian, with his desire to kill half of all living things to remove suffering). It still finds echoes in certain quarters, including some environmentalist factions, but the real concern in rich countries today is that we are having too few children rather than too many.

The average fertility rate in the 38 countries of the Organisation for Economic Co-operation and Development has fallen by more than half in the past 60 years: from 3.3 in 1960 to just 1.5 in 2022, well below the “replacement level” of 2.1, meaning the level that maintains the population at the current rate.

Overpopulation is a real concern in many poorer countries, and fortunately the solutions here are far more palatable than those advocated by Malthus. The most powerful way to reduce fertility is to improve childhood survival rates, because parents overcompensate for high mortality levels by having more children. In a fortunate paradox, then, the solution to overpopulation has turned out to be almost the exact opposite of what Malthus believed.

Ciarán Casey does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.