For more than 200 years there have been people who have argued that the world is overpopulated, and that this is the main cause of poverty, unemployment, homelessness and damage to the environment.

In 1798 an English clergyman, the Reverend Thomas Malthus, published his Essay on the Principle of Population. He argued that population always tends to grow faster than food production and that therefore, without severe moral restraint, mass poverty and famine were inevitable.

Now, with food prices rocketing, oil at $140 a barrel, recession looming and hostility to immigrants being whipped up all over the place, addressing this argument is more urgent than ever.

Socialists, beginning with Karl Marx and Frederick Engels, who called Malthus’s theory “a slander on the human race”, have always rejected the overpopulation argument.

It is false on principle because it inverts the relationship between human beings and their means of subsistence, and it is also completely at variance with historical and contemporary facts.

World population stands at about 6.7 billion. It is growing, but it is not exploding. The rate of growth is in fact declining.

Between 1950 and 2000 the global population grew from 2.5 billion to 6.0 billion – an increase of 140 percent. But in the 50 years to 2050 experts on population predict it will rise by just 50 percent, and in the fifty years after that by 11 percent.

The reason for this pattern is simple – world birth rates continue to exceed death rates, but birth rates are falling because, as living standards, education and medical care improve, women have fewer children.

The growth in population is not outstripping food production. Between 1950 and 1970, world food production rose by 250 percent, completely outstripping population growth over the same period.

There is no world food shortage. On the contrary there is more than enough food produced in the world to supply everyone with a decent diet.

Density

If people are starving and there are food riots breaking out across the world, this is because of the inability of the poor to pay the prices demanded by the market. In other words it is because of capitalist economics and capitalist politics.

Nor is the prosperity of individual countries determined by, or even significantly related to, their population size or population density.

For example Bolivia in South America has a population density of 8.4 people per square kilometre, and a GDP per capita (the total amount of goods and services produced divided equally among the population) of £2,030.

Venezuela, conversely, has a population density of 28.5 people per square kilometre and a GDP per capita of £6,190. Therefore Venezuela is more than three times more densely populated than Bolivia, but is three times as rich.

The lack of a link between population density and the wealth of a society can also been seen if we compare two Asian countries. India has a population density of 345 people per square kilometre, broadly similar to Japan at 343. Yet India has a GDP per capita of just £1,370, compared to Japan’s £16,750.

India and Japan have similar population densities, but very different histories – India was colonised, while Japan was a colonising power – and hugely different levels of economic prosperity.

What these examples prove is that it is economics, politics, imperialism and war – in a word, history – that determine a country’s living standards, not the size of its population. And that fact goes to heart of what is wrong with the whole overpopulation argument.

Its proponents take a country’s goods – its food, houses, health service, jobs, wealth and so on – as more or less fixed in quantity to which the population should be adjusted. In reality people produce all these goods, so an increase in the number of people means not only increased demand for these products, but also an increase in the number of people available to produce them.

If this were not so the history of humanity would be an unmitigated disaster of increasing impoverishment and unemployment as the world population increased from around 200 million in 1BC, 310 million in the year 1000, 978 million in 1800, to 1,650 million in 1900. In fact, the basic tendency has been for humanity to get richer (albeit incredibly unequally), survive better and live longer – which is precisely why the population has increased!

What prevents the process from being even or harmonious are the contradictions inherent in class society, especially capitalism with its periodic wars and economic crises. Because capitalism makes production dependent on profit, production falls when rates of profit fall, regardless of population size or the effects on the population in terms of poverty, unemployment or starvation.

The politics of this whole question are at their sharpest over the issues of climate change and immigration. Many greens and other genuinely concerned people who might broadly accept the argument presented so far begin to change their tune when it comes to the environment.

The earth’s resources are finite, they say, and human beings are using them up. The more human beings there are, the more pressure on these resources, and unless population growth is stopped, the planet will be destroyed. But this reasoning is as false as the arguments already refuted and repeats the same basic error.

Emissions

Yes, the earth’s resources are finite. But this does not mean that human activity is anywhere near reaching those limits, either now or in the foreseeable future.

This is because while some resources, such as oil, may be fixed in quantity, others such as the power of the wind or tides can only be harnessed or “produced” by human labour in the same sense that food is. Consequently an increased population means potentially more labour to create more of these resources.

Where the carbon emissions that generate climate change are concerned, it is not people as such that produce these emissions but, overwhelmingly, the burning of fossil fuels. The reason our societies are locked into the burning of these fuels, despite the knowledge that it is leading to catastrophe, is not due to the size of their populations but the crucial role fossil fuels play in the profits of big business.

Those who cite population reduction as a way to stop climate change are really saying they find it easier to conceive of “losing” a billion or so people, rather than contemplate overthrowing capitalism, or even seriously challenging its priorities.

When it comes to immigration, the overpopulation argument is largely a fig leaf for xenophobia and racism – though proponents of this argument always insist it is a question of numbers, not of race. Britain is simply full up, they say. The falsity of this claim is obvious when one thinks of the vast empty spaces in the Scottish Highlands, Mid Wales and North Yorkshire.

Clearly what they mean to say is that the country is full up because of the lack of jobs, homes, and services. But this brings us back to the original argument that the quantity of these things is not fixed. People, including immigrants, produce them and it is therefore utterly wrong to blame unemployment or housing shortages on immigration.

Underlying the claim that immigration is causing unemployment is the idea that some people (such as foreigners or black people) are not entitled to jobs, or at least are less entitled than others (such as the British).

Both the absurdity and the racism of this way of thinking is neatly exposed if one simply substitutes some other group (red haired people, for example) instead of foreigners. Try saying, “Its those red haired lot that I blame. There are two million gingers and two million unemployed – kick out the gingers and we’d all have a job,” and the ridiculous nature of racism is clear.

Unfortunately in a period of economic and social crisis it is much easier for such a ludicrous argument to gain ground, particularly among those who are forced to complete for life’s basics.

In the end all the claims about overpopulation boil down to same thing – blaming people for the problems of the system. That is why socialists should reject them root and branch.