Malthus Was Wrong. Is He Still Wrong?

In 2004 History Future Now went on a mission to read the most influential books on economic and philosophical theory. Books selected were deliberately from all spectrums of economic thought and included David Ricardo’s The Principles of Political Economy and Taxation, John Galbraith’s The Affluent Society, Milton Friedman’s Capitalism and Freedom, Thomas Paine's The Age of Reason, John Maynard Keynes' The General Theory of Employment, Interest and Money, Adam Smith’s Wealth of Nations, Karl Marx’s Capital and many others.

One volume which stood out in particular was An Essay on the Principle of Population, by the Reverend Thomas Robert Malthus.   He famously predicted that food production increases would not keep up with population increases, resulting in gigantic, inevitable, famines.

Malthus lived in a world of about 1 billion people.  Today there are over 7.3 billion people, so his prediction was clearly very wrong.  History Future Now will try to understand why he was wrong and then asks a critical question: is he still wrong?

Before we go into that it would be useful to provide some background on Thomas Malthus and the core ideas that he explored in his writings.

Thomas Robert Malthus

Malthus was born in a country house near Westcott, Surrey, England in 1766, the sixth of seven children in a land that was fundamentally agrarian, but buzzing with ideas and innovations.  He died in Bath, England, aged 68, in December 1834 just as the industrial revolution was picking up steam. He was initially home educated, went to Dissenting Warrington Academy and then up to Cambridge University where he studied Latin, Greek and mathematics. In 1798, he became an Anglican curate back in his home county of Surrey.

In 1798, he published An Essay on the Principle of Population which he then updated six times, the final version emerged, after years of additional research and responses to feedback, in 1826.  One of the reasons for his writings was due to his objection to some of the more utopian works on humanity by William Godwin (Enquiry concerning Political Justice in 1793) and the Marquis de Condorcet (The Future Progress).

Malthus is most famous for a passage in which he writes that:

The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race. The vices of mankind are active and able ministers of depopulation. They are the precursors in the great army of destruction, and often finish the dreadful work themselves. But should they fail in this war of extermination, sickly seasons, epidemics, pestilence, and plague advance in terrific array, and sweep off their thousands and tens of thousands. Should success be still incomplete, gigantic inevitable famine stalks in the rear, and with one mighty blow levels the population with the food of the world.

While this inevitability of overpopulation resulting in premature death due to war or famine makes him well remembered today, one of his central concerns was about the fate of the poor in society, and he claimed that there would always be a poor underclass.

He describes a cycle whereby an increased population would depress the value of labour, causing poverty and hardship.  The population would stagnate for a period, but the resulting cheap labour would encourage agricultural expansion, resulting in more food and thus cheaper food, thus encouraging the population to increase and the cycle would continue:

The food therefore which before supported seven millions must now be divided among seven millions and a half or eight millions. The poor consequently must live much worse, and many of them be reduced to severe distress. The number of labourers also being above the proportion of the work in the market, the price of labour must tend toward a decrease, while the price of provisions would at the same time tend to rise. The labourer therefore must work harder to earn the same as he did before. During this season of distress, the discouragements to marriage, and the difficulty of rearing a family are so great that population is at a stand. In the mean time the cheapness of labour, the plenty of labourers, and the necessity of an increased industry amongst them, encourage cultivators to employ more labour upon their land, to turn up fresh soil, and to manure and improve more completely what is already in tillage, till ultimately the means of subsistence become in the same proportion to the population as at the period from which we set out.

This population expansion, stagnation and expansion cycle is very reminiscent of the boom and bust cycles in an economy and so it is not surprising that Malthus was so influential on other thinkers ranging from Keynes, Marx, Wallace, Mao Zedong and even Darwin.

Malthus believed that to stop this cycle of scarcity workers should be encouraged to postpone marriage and practice celibacy whilst in marriage to keep population numbers in check.  If they did not keep their numbers in check by their own measures, they would be kept poor, or even worse, the positive checks of war, sickness and famine would kick in, bringing even greater misery.

Many contemporaries, who included Godwin, Marx and Ricardo, strongly disagreed with his views on restricting population or that there would be a permanent underclass.  Friedrich Engels, the German-British industrialist who funded Marx, was particularly scathing as he believed Malthus ignored the power of science to increase food production.  Admittedly, it is worth noting that Engels was born in 1820 and so was far more aware of the transformative power of coal and industrialisation than was Malthus, who lived in a primarily agricultural society. Others were horrified at Malthus’ view that small pox vaccinations were a bad thing for society as it just enabled more people to live, bringing in greater catastrophe in the future.

So why was Malthus wrong?

The world’s population had been growing by about 100 million every century since 1500 and was at around 700 million shortly before Malthus’ birth in 1766.  While Malthus recognised that the population had slowly been increasing, he was not in a position to anticipate three major changes to the amount of food available that occurred shortly after he made his predictions.

World population stood at 1 billion by 1804 and 2 billion slightly over a century later, 10 times more than the pre industrial revolution average increase of 100 million per century.  From 1900 the pace accelerated, from 1.6 billion in 1900 to 6.1 billion in 2000.   Since 1960 the world’s population has been increasing by about 1 billion per decade.

The three major changes were mechanisation and fossil fuels, food imports and increased land for food, and improved yields per acre.

Mechanisation and fossil fuels

Fossil fuels, first in the form of coal and then in oil and gas, revolutionised farming and its productivity.  When societies relied on human and animal power there were significant limits to how much surplus food could be generated per farmer.  With mechanisation, first with steam-powered devices and then with vehicles using internal combustion engines, farmers were able to significantly increase the food output per farm worker.  In developed countries, 2-4% of the entire population is now able to provide enough food for the rest of their country, mainly thanks to mechanisation.

Fossil fuels are not just used for power, however.  Natural gas forms - with nitrogen – the raw ingredient for the creation of ammonia based fertilisers, thanks to the industrialisation of the Haber process in 1913.  This process helped to significantly improve yields of food on agricultural lands all over the world.

Increased area of land under cultivation

Malthus grew up in a country that was isolated from a food perspective from other countries.  The bulk of the food that England consumed was grown domestically.  International trade was very vigorous, but was mainly confined to very high value products that could be transported on ships – like sugar, coffee and tobacco.  Bulk transportation of food, such as grains, was relatively uncommon at the time of An Essay on the Principle of Population‘s publication in 1798.  By 1815 it was sufficiently common that Britain introduced Corn Laws restricting grain imports, which caused riots in towns.

This has clearly changed.  The colonies in the New World were relatively unpopulated and when Europeans brought over European style farming to these areas, combined with mechanisation, it resulted in the massive increase in the amount of land available for farming.

Food is now transported in bulk all over the world, ensuring that any surplus food is sold into a web of interconnected markets.  This helps drive down food prices and helps increase the availability of food for all, even allowing for the impact of bad harvests in one area to be mitigated by good harvests in other parts of the world.  America, Argentina and Brazil, for example are now major food exporters for the entire world.

Interestingly, Malthus supported the Corn Laws that were introduced in 1815, restricting corn imports to England, while most free trade economists argued for its abolition.  He argued that the more foreign corn England imported the more dependent it would be on foreign imports.  This would mean that England would be increasingly held captive to foreign politics and vulnerable to trade restrictions that would emerge in the event of a food shortfall in another country.

Improvements in yields per acre

The third major change is an improvement of yields per acre.  Yield has gone up due to better equipment for ploughing and monitoring the soil, artificially selected plant strains, fertilisers, pesticides and other improvements to the science of crops.  Hybrid and genetically modified plants promise to further improve the yield from a given patch of land. Improved water pumps, have also massively increased yields in arid parts of the world such as the US, China, India and Saudi Arabia; places that were originally unsuitable for farming but are now highly productive thanks to irrigation from water 1-2 miles below the ground’s surface.

Does this mean that Malthus will always be wrong?

Unfortunately, just because Malthus was wrong 200 years ago it does not mean that his theories will always be wrong. The three main drivers of agricultural growth are stalling and many of them are one offs, never to be repeated again.  What is changing?

First, improvements in productivity due to mechanisation are now relatively marginal. When Malthus was young, 90% of the country would have been involved in farming. In most developed countries that number is now between 2-4% of the population.  Even if you had a 50% improvement in farming mechanisation and productivity per person, this would mean that the numbers involved in farming would drop to 1-2% of the population.  An improvement that is irrelevant in the scheme of things.

Second, the world saw a huge increase in new land available for agriculture thanks to New World colonies in North, Central and South America.  That land was a one off and we are not anticipating the discovery of a new continent any time soon.  As the population of the world increases, the amount of new land is not expected to expand, but rather contract.  This contraction is due to the fact that most cities are located in proximity to prime agricultural land.  As cities get bigger they expand over this prime land.  Sea level rises are also likely to impact agricultural lands around the coast, with particular impacts around deltas.

Third, improvements in yields per acre are also under threat.  Much is made about genetically modified crops, with the anticipation that they will radically increase yields over and above existing modern strains of crops.  This is mainly true.  But even Monsanto does not see huge productivity growth in idealised locations and more land is no longer “ideal”.

There are multiple issues. One is that improvements due to improved strains are not that fast. Second is that land quality is deteriorating due to soil erosion and salinisation so any improvements from new strains are likely to be offset by deteriorating land quality. It is also worth noting that if GM crops were very successful and planted in large quantities it would produce a dangerous monoculture.  Monocultures are more susceptible to disease and thus it would increase the likelihood of disease wiping out that entire global crop.

Huge irrigation schemes in the US, China, India and other parts of the world are also under threat as much of the water comes from underground aquifers.  These aquifers get replenished over thousands of years and current levels of extraction significantly exceed the replenishment rate (see article).  Many countries rely on glacial melt to feed their river systems and monsoon rains to water their crops.  Changes in climate are already affecting weather patterns which in turn makes these natural watering systems less reliable.

Finally, as countries get richer, access to variety of foods improve and people want to eat more protein.  Growing crops like alfalfa, soya beans and maize for animal feed reduces the food available for direct human consumption. Growing corn for biofuels will clearly have to stop.  Perhaps also the production of animal fodder. 

This is a bleak assessment of food availability: land availability is declining, not increasing, mechanisation is producing diminishing returns, yield improvements due to genetically modified crops are lower than hoped for and are likely to be offset by declining soil quality and water availability.  Malthus would be nodding his head in sad agreement: famines are more likely than food abundance.

So what about Engels?

Frederich Engels was particularly critical of Malthus and believed that man’s ingenuity and science would solve the world’s food shortages. So what are the wild cards that might make Engels right and Malthus wrong in the future?  Here are some possibilities.

Factory grown food crops

When you think about it, growing food in fields is a very inefficient use of space and resources.  There are a number of companies that are developing “factory farms” with high value crops being grown in nutrient mixes that are perfect for the plants being grown.  Some even have rotating growing levels, which allow for vertical farming.  This allows for more food to be grown in a given area and for diseases to be controlled.  Will this ever be as productive as growing food on millions of acres of land? Probably not, but it might make a difference.

Improved irrigation

A lot of water is wasted in irrigation. Some of the water is absorbed by the plants but much of it evaporates leaving minerals behind which cause  salinisation of the soil.  Improved irrigation that gets more water to plant roots and nowhere else is of great benefit – but installing those systems will be expensive and will increase food costs.

Africa and Siberia

African soils are, in most places, not ideal for intensive farming.  Weather patterns make it especially difficult, though parts of Africa could be farmed more intensively in the short term.  However, Africa is expected to be especially vulnerable to climate change (see US Department of Defense report).  As global warming accelerates, however, it may be possible that much of the frozen tundras of Canada and Siberia might thaw out, releasing not only millions of tonnes of methane, but also unlocking much of that area for agriculture.

Star Trek Replicator

Finally, and on a more optimistic note, we have Michio Kaku, Professor of Theoretical Physics at CUNY, who says that Star Trek style replicators, which build products from an atomic level, are not that far off in the future:

… we have nanotechnology, and with nanotechnology, perhaps, who knows, maybe in 100 years, we’ll have something called the replicator.  Now the replicator is something you see in Star Trek.  It’s called the molecular assembler and it takes ordinary raw materials, breaks them up at the atomic level and joins the joints in different ways to create new substances.  If you have a molecular assembler, you can turn, for example, a glass into wood or vice versa.  You would have the power of a magician, in fact, the power of a god, the ability to literally transform the atoms of one substance into another and we see it on Star Trek.

And that, lets face it, sounds pretty great!