2: The Increase of Population v. Food
A key point of Malthus's thesis is that an unchecked population increases geometrically whereas subsistence merely increases arithmetically. In this chapter, he will consider the accuracy of these assertions.
The Increase in Population
There has not been a state in which the increase of population was completely unchecked. It is "the dictate of nature and virtue" among people, even where the condition of marriage is not prescribed, seems to be monogamy.
On a practical level, population is driven by economics: given a fixed amount of resources, each additional person decreases the share given to each. Hence, the upper classes restrict their breeding to preserve their standard of living whereas the lower restrict their breeding because their meager resources cannot possibly be further divided to feed an additional mouth.
(EN: One important point here is that Malthus speaks of natural inclinations, not the consequence of Law. I've seen it asserted that Malthus espouses the view that political force is necessary to keep people from breeding like rabbits, but at least for now he uses the word "state" with a lowercase "s" - as such, it is "the state of society" rather than a political State.)
He then looks to the United States as a nation where population advances rapidly - as the means of subsistence (land and natural resources) are so abundant that there is little fear of being able to provide amply for a family. People there marry early and raise larger families and the increase in population is greater than in older or poorer nations.
In the US, the population has been observed to double itself in about 25 years. It's in this sense that Malthus means geometric increase: instead of growing arithmetically (1-2-3-4) it doubles itself (1-2-4-8).
(EN: This, too, is an error. The calculations may have seemed accurate given the data of the author's time, during which the US was a young nation undergoing rapid expansion. Looking into history, the 1790 census shows about 4 million - so if this postulate held true, the 2015 population of the US would be just over 2 billion ... but the 2010 census suggests around 300 million.)
The Increase in Food
Regarding the increase in food, Malthus considers England: by giving there greatest possible encouragement to agriculture, he believes it would indeed be feasible to double the amount of cropland in England. However, he does not believe it could be redoubled in another year - the most fertile lands being claimed, there is not quadruple the amount to be had, and it would quickly reach the point where every acre of land would be converted to a garden.
As such, he asserts that the increase in cropland may only be arithmetical, and has a very firm limitation in the fixed amount of arable land.
(EN: The basis for this postulate seems more to do with guesses and beliefs than mathematical calculation. And while the guesses might be reasonable - I haven't done the research to check on them - it is also based on the productivity of land being fixed on a per-acre basis: it ignores the contribution of labor, and the advancement of science and technology to produce more food per acre.)
Combined Effects
Considering the progression of the two ratios, Malthus projects:
- Presently: 7 million people, food for 7 million
- 25 years hence: 14 million people, food for 14 million
- 50 years hence: 28 million people, food for 21 million
- 75 years hence: 56 million people, food for 28 million
- 100 years hence: 112 million people, food for 35 million
He acknowledges the effects of emigration and trade between England and America: specifically, in the England exports her surplus population to America and imports food for the remainder from America. And therefore it is not from her own strength that England sustains even its present population, but by a parasitic relationship with a nation that is stronger in these two regards.
However, when you scale this up to the world, in which all people reside and on which all crops are grown, and from which no importation or exportation is possible, it is evident that a population that doubles will quickly outstrip the capacity of the land to provide for them.
In once century, the ratio of people to food is 8:4; two centuries 256:8; three centuries 4096:13. "In two thousand years, the difference would be almost incalculable."
Checks Upon Population Increase
The human species can only increase to the extent that it is able to sustain itself, and there is a constant operation of a "strong law of necessity" acting as a check upon population.
In the animal kingdom, creatures are both compelled and restricted by their instinct, which is by nature suppressed when there is want of room and nourishment. Mankind has no such instinct, no breeding season, and is guided by logic and reason to belabor the decision of reproduction.
The rational man recognizes that a child is a burden to which he must tend. He must consider whether he has or is able to obtain sufficient food to support an additional person, whether he is willing to undertake the labor to produce more, whether he and his family can make do with less to provide an additional share. Ultimately, he recognizes that there is a limit to his productive ability beyond which expanding his family will produce poverty and misery.
Such calculations effectively prevent most civilized nations from reproducing to the full extent to which they are biologically capable, but historically it has not prevented them from reproducing to an extent that domestic resources cannot sustain the population. Colonialism and foreign trade are present, but temporary, alternatives to war and famine that have historically resulted.
Even domestically, the disparity in the wealth of the population is clear: the work product of all is not merely shared out in equal measure, but is entirely disproportionate: the poor toil harder for a smaller share and the wealthy are less burdened and enjoy a greater share. The tendency of the poor to have more children than the wealthy is one of the prime causes, and one that is exaggerated significantly over the course of generations.
Historical evidence, however, is spotty: "The histories of mankind that we possess are histories only of the higher classes" and there are not many historical accounts of the lives of average or poor citizens. As such, we are left with the impression of the past as a time of happiness and plentitude.
But even in that, we can see evidence of the variations in population Where historians write of famine, warfare, scarcity, and other such things, it is plainly evidence of an imbalance between population and production. We can also examine the history of legislation, where laws are clearly written to mitigate the negative effects of an imbalance of population and food. The legal records of the sale of goods, the negotiation of wages, and the like all speak to the scarcity or plentitude of goods and labor and the negotiation and mitigation of the imbalance between them.
These measures aside, what remains plain is that the population cannot increase without the means of subsistence. Measures undertaken to avoid that simple truth have created much misery and had but a temporary effect until the two factors returned, often of an accord other than the dictates of law, to a harmonious balance.