Where Malthus was Wrong – and What he got Right

Thomas Malthus was the 18th-19th century economist who is most widely known for making a bold prediction which turned out to be spectacularly wrong. He  suggested that an exponentially rising population could not be sustained because agricultural production would not be able to keep up with it. he predicted that periodic crashes in population level and increased poverty would be the inevitable result. But on the contrary, over the next hundred years the population of Britain increased from about seven million to more than 41 million. And in the following century it increased further to over 60 million – and the average prosperity of even the poorest of English workers had advanced to a level that would have been unimaginable in 1800. Because reality diverged so greatly from his forecast, his name has become a term of ridicule, applied to any commentator who suggests that unlimited global financial growth may not be possible.

Malthus studied at Jesus College Cambridge, where he distinguished himself in English, Latin and Greek. He was awarded a high first class honours degree in mathematics, and elected as a fellow of the college. In common with many academics at that time he took holy orders, and served for a while as a parish priest. While performing that role, he noticed that he was carrying out significantly more baptisms than funerals – and from his mathematical understanding he realised that this would lead to an exponential growth in the population of the country. Suggesting that agricultural production could not possibly grow at more than a modest linear rate, he concluded that the level of the population would shortly rise to a point where it could no longer be supported by the available food, and that poverty and misery would surely result. He published these findings in An Essay on the Principle of Population in 1798, with several updated editions over the next thirty years.

Malthus’ ideas became more widely known and debated because both Charles Darwin and Alfred Russell referred to his work as an inspiration for their theories of evolution by natural selection. However, the rising levels of population of the country coupled with growing average prosperity undermined the acceptance of his theory. The mainstream economic view persisting from the mid 19th century to the present day argues that indefinite unlimited growth can be supported by a combination of novel technology and the operation of free market pricing. Consequently, anyone who suggests otherwise risks being ridiculed, and accused of falling into “the Malthusian Fallacy”.

But perhaps his critics have been both unfair and premature? The core point that an exponential rise in population would cause it to overtake the capacity of the country to produce enough to feed it was not disproved by the events of the next century. On the contrary it was vindicated. Britain did not – and could not – produce enough food for the 41 million inhabitants it had in 1900. The development that allowed it to feed everyone, and for large sections of the population to become much more prosperous, was the dramatic success of the Industrial Revolution. British manufactured goods were exported on a vast scale, and food grown in other countries imported in exchange. Although the Industrial Revolution was getting under way at the time Malthus was writing, nobody could have predicted the impact of the next few decades’ developments. Similarly, we have been living through the early years of the Cybernetic Revolution, and cannot know how social, cultural and industrial arrangements are going to develop over the next fifty years.

However the issues we face now are global in scale, not national. There is no other planet that we can turn to when we reach the limit of our food supplies. Even with the current population of over 7.5 billion, there is enough food being produced for everyone; the reasons that millions are starving are political, institutional and financial. But it is also true that there is a finite area of cultivated, or potentially productive land. Some changes in farming methods have delivered considerable increases in crop yields, but there will still be an upper limit at some point. And unfortunately some of the modern farming techniques are turning out to be short-term solutions. We may be producing more food today – but at the cost of damaging the soil in ways that will ensure falling productions within a generation or so. Modern techniques are also heavily dependent on energy inputs from fossil fuels – not just in the obvious reliance on fuel for all that agricultural machinery, but also in the manufacture of all the fertilisers, weedkillers and insecticides. As these fuels become scarcer and more expensive, many of these recent gains may be reversed.

The population of the world as a whole has actually been growing at more than exponential rates. It took 123 years to double from 1 billion to 2 billion; 61 years to double from 1.5 to 3 billion; and 39 years to double from 3 to 6 billion. Even if it maintained “merely” exponential growth at the latest rate, we would reach 15 billion by 2055, 30 billion by 2094, and 60 billion by 2133. Even the greatest optimists must surely agree that sometime along that path we will exceed the capacity to grow enough food to nourish them all. If we haven’t brought the growth under control by reducing the birth rate, it will come down by an increase of the death rate – through starvation, disease or warfare.

And if we want to provide the world’s poorest with more than a meagre poverty-stricken existence – what would it take to provide this expanded population with the comforts and luxuries that we take for granted?

The next section in this thread will describe a computer model that maps the interactions between population, food production, industrialisation, energy consumption and pollution. This can be used to explore the likely consequences of various policy choices over the course of the next century. The best way you can prepare yourself for the disruptions that are coming over the next decade or to is to have a realistic grasp of what is actually possible within the resources of this finite planet.

This essay is part of my forthcoming book The World in 2100: What might be Possible for Humanity? It is within the thread on The System of the World, which – in conjunction with the other six themes of the book – provides a comprehensive survey of the position we find ourselves in at this critical time in human history.

If you haven’t already done so, you can register to receive a free review copy just before it goes on general sale later this year. Registering will also take you straight to Chapter 1 – The Foundations which will give you an overall idea of what the book will cover.


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