What "Malthusian" Means

Today, I am returning to the theme of the past few weeks of sustainability, and in particular the question of what the limits are to scaling in human societies. Recent posts on this subject include internal limits to growth and peak oil. This week, we are going much farther back in time, to the essay that put the word “Malthusian” in our vocabulary, “An Essay on the Principle of Population” by Thomas Robert Malthus (Malthus (1798)).

I toss the word “Malthusian” around frequently in my writing with the expectation that the word has a clear and understood meaning. Many writers, including myself, use the word sloppily and often as a slur. The word has also evolved in meaning, as I noted last month. While words do have to evolve to fit changing mores and knowledge, the process can obscure their original meaning. Those of us who discuss resource limitation issues who have not read Malthus’ 1798 essay, including me until this past week, don’t know all that it really says. The essay is flawed, just as is the works that it inspired, but we can also learn from it.

Thomas Robert Malthus in 1834, the year of his death and 36 years after the publication of his most famous essay. Image from Wikipedia.

Population Dynamics

Even those who have not read the essay might know the basic premise. Left to its own devices, the population in a human society should grow exponentially, while the food supply grows linearly. This necessarily means that the food available per capita must eventually decrease to a subsistence level. Malthus states in the introduction,

Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio. A slight acquaintance with numbers will shew the immensity of the first power in comparison of the second.

The words “geometrical” and “arithmetical” are often tossed around with the assumption that the reader has an understanding of the relevant mathematics, but let us review that.

In Malthus’ usage, and also if you remember your high school math classes, a geometric sequence is one in which every term is the product of the previous term and a fixed number. If the ratio is 2, then an example of a geometric sequence is,

1, 2, 4, 8, 16, 32, 64, 126, 256, …

An arithmetic sequence is one in which every term is the sum of the previous term and a fixed number. An example is,

1, 2, 3, 4, 5, 6, 7, 8, …

These sequences are identical for the first two terms. At the third term, the values are 4 and 3 respectively, which don’t seem so far apart. But by the eighth term, the respective values of 256 and 8 are very far apart, and the ratio only becomes more extreme beyond that. It can be shown that as long as the geometric ratio is greater than one, the geometric sequence always dominates the arithmetic sequence eventually, and eventually by an arbitrarily high ratio.

Recall that the first sequence represents population and the second is food supply. Suppose that the numbers are such that one unit of food per person is a superabundant supply, and one tenth of a unit is the bare minimum for survival. In the first time step, the society is well fed. It is equally well fed in the second time step, and in fact it is even better fed in the intervening time. The quantity of food per capita then diminishes, though this doesn’t seem to be a great problem in the third and fourth time steps. Hunger begins to step in at the sixth time step, and by the eighth, the society is experiencing full-blown famine.

Obviously this cannot continue. What must eventually occur is what later writers have called a “Malthusian catastrophe”, in which population is held back through either misery or vice. Most contemporary authors focus on misery—disease, famine, or war—and overlook the second. We’ll come back to that shortly.

But first, why do population and food supply grow as Malthus predicts? For population, the argument is easy to understand, even if it is not correct. Malthus posits that in the absence of a limiting factor on population, people will marry early and have as many children as they reasonably can. This is not the place for a detailed discussion of population dynamics, but suppose that every married couple, at age 25, has four children that go on marry and have children of their own (Malthus does indeed assume that children are born into wedlock; we won’t digress to quibble about that here). Since two parents produce four children, the population doubles after 25 years. The doubling time can be lengthened or shortened by having fewer or more children, or by having them at a later or earlier age.

The population of Great Britain in 1798 was about 10 million people (Malthus puts the number at 7 million). Malthus suggests that in the absence of limiting factors, a doubling time of 25 years is reasonable. There has not been great population pressure in Britain since 1798, and so that would put the population of Great Britain at about 5.4 billion today. Actual population is about 68 million, which is a doubling time of around 81 years.

According to Our World in Data, the crude birth rate (births per 1000 people) peaked in England and Wales in 1816, not long after Malthus wrote his essay. That number in 2015 was less than a third of its 1816 value. So Malthus was wrong about birth rates. Or was he? We’ll see what he meant by vice, the neglected second half of the formula, in “misery and vice” in a bit.

Malthus seems to assume, without explanation, that arithmetic growth in the food supply is to be expected. It is unclear to me how he came to this conclusion, and my guess is that he simply went for a simple mathematical formulation to make the point. Malthus was not a mathematician, nor are mathematics a feature of the essay. This assumption is not acceptable for any serious modeling, but for the purposes of the essay, it is good enough.

Incidentally, Malthus was not concerned about the availability of raw materials. In Chapter 5, he states,

It should be remembered always that there is an essential difference between food and those wrought commodities, the raw materials of which are in great plenty. A demand for these last will not fail to create them in as great a quantity as they are wanted. The demand for food has by no means the same creative power.

This is in contrast to the Club of Rome’s The Limits to Growth, which considers the availability of raw materials to be a more pressing threat to growth than the food supply. Thinkers who are optimistic about resource supply, such as Julian Simon, might argue that Malthus was right about raw materials, and he should have applied the same reasoning to the food supply.

“Misery and Vice”

According to Malthus, there are two factors that must inevitably limit population growth.

The first, misery, is no surprise to people who have been around the block with these issues. Neo-Malthusian writers, such as The Limits to Growth authors, Paul Ehrlich, and many authors around the peak oil movement, for instance, have predicted that the mismatch between supply and demand for critical commodities will result in severe misery, up to and including mass death. Malthus saw famines and massive epidemics, which were more recent for him than for us, as the mechanism by which misery would play out.

Rather than being in a perpetual state of misery, Malthus argued that society should go through oscillation. Deprivation would lower birth rates and increase death rates for a time, leading to population being well under the carrying capacity before it starts to rise again. Malthus devotes considerable discussion to why the regular oscillations modeled in his essay do not clearly manifest themselves, but the pattern of population growth → catastrophe → decline → abundance → growth can be observed at least in an irregular sense in the pre-industrial world.

The second, vice, is more subtle. A cleric and devout Christian, Malthus believed that the normative lifestyle was for young people to marry and have children. “Vice” is deviation from this norm. Although he didn’t use the term, Malthus would thus assess that the condition of subreplacement birth rates in much of the modern world is a Malthusian catastrophe, as a deviation from virtuous norms of family, and a vindication of his model.

Malthus observed that in European countries, young people, wanting to be good parents, consider their ability to provide for offspring before having children. Norms in advanced European civilizations, which filter down from the aristocracy, hold certain expectations of a standard of living that poorer people may be unable to provide, thus inducing them to have fewer children or none at all. Malthus assess that less civilized hunter-gatherer nations such as North American Indians and nomadic herdsmen such as the Huns and the Mongols, do not have such restrains and suffer for it, or inflict suffering on others as was the case with the Hun and Mongol conquests. The argument thus presages demographic transition theory in a more sophisticated way than one might expect. But there are a few problems.

First, to get the obvious out of the way, Malthus writes about various peoples of the world using archaic language, much of which would not be considered to be politically correct today. Aside from that, much of his understanding of history, anthropology, and demography has long been superseded.

Second, Malthus’ characterization of “vice” is based on an idiosyncratic morality that would be a minority, if not a fringe view today. The prevailing view among the world’s opinion-makers is that the demographic transition is a virtue, not a vice, because it liberates humanity from the specter of overpopulation and represents greater freedom for women, such as argued by Campbell, Prata, and Potts (2013). If not a virtue, than at least the shift to smaller families is morally neutral, as decisions about marriage, family, etc. should be personal affairs.

Third, Malthus’ model has no predictive power. The conclusion that there must be some limiting factor to exponential population growth is too banal to merit serious discussion, and the framework of “misery and vice” admits almost any explanation for eventual stagnant or declining population.

Social Policy

In his essay, Malthus ventures into several aspects of social policy in Britain at the time, most especially the Poor Laws, for which Malthus has great contempt. The Poor Laws in Britain were a series of measures to provide relief to the poor, with the requirement that able-bodied people work in workhouses, regarded as unpleasant employers of last resort.

Malthus had several objections to the Poor Laws, some of which resemble modern social conservative critiques of the welfare state. Malthus argued that the Poor Laws discouraged savings and responsibility among the working class. With colorful, curmudgeonly language that borders on misanthropic,

The labouring poor, to use a vulgar expression, seem always to live from hand to mouth. Their present wants employ their whole attention, and they seldom think of the future. Even when they have an opportunity of saving they seldom exercise it, but all that is beyond their present necessities goes, generally speaking, to the ale-house. The poor laws of England may therefore be said to diminish both the power and the will to save among the common people, and thus to weaken one of the strongest incentives to sobriety and industry, and consequently to happiness.

With population pressures in mind, Malthus considered inflation. Since relief for the poor would do nothing to increase the supply of food, the result would be more money chasing a fixed supply of food, thus raising prices. This argument resembles the abundance movement’s critique of a subsidy-first approach to health care and housing costs, though their solution is generally to lift unnecessary barriers to the supply of these goods, not to restrict demand.

Most seriously, Malthus is concerned that the presence of welfare will free the working class of the financial risks, and thus of hesitation, from having more children. If poor relief induces population growth, then the poor will be worse off overall for it. This is similar to Garrett Hardin’s Lifeboat Ethics (Hardin (1974)), with the blunt subtitle “the Case Against Helping the Poor”.

Any reference to a state program of population control, analogous to China’s One Child Policy and forced sterilization in India, is nowhere to be found in Malthus’ essay. This is probably because state capacity of European nations in the late 18th century was not sufficient to even contemplate such a program. Had he contemplated coercive population control, I suspect Malthus would have been against it on the grounds of personal freedom. This is based on comments on a shorter work day,

Those that had large families would naturally be desirous of exchanging two hours more of their labour for an ampler quantity of subsistence. How are they to be prevented from making this exchange? it would be a violation of the first and most sacred property that a man possesses to attempt, by positive institutions, to interfere with his command over his own labour.

Very much distributed through the essay is a deep contempt for manufacturing and urban life. Presaging modern debates around the propriety of gross domestic product as an economic indicator, Malthus argues that manufacturing employment should not count toward a nation’s wealth (GDP in modern parlance), as it does nothing to improve the standard of living for the average person, and only agricultural employment should count. Needless to say, this argument did not gain much traction among economists. Nowadays, as manufacturing employment has peaked and declined in wealthy countries, one is more likely to here these critiques directed at service sector and swathes of white collar jobs, and that manufacturing, unlike these, is “real” wealth. Incidentally, it is well-known that birth rates tend to be higher in rural areas than in cities. This has been a universal pattern across regions and time periods, and I find it hard to imagine that Malthus was unaware of it.

On Progress

Highly optimistic ideas of social progress were part of the intellectual milieu in the Enlightenment era, and Malthus was not having any part of it.

A motivation for the essay was a reaction against Marquis de Condorcet’s book, Sketch for a Historical Picture of the Progress of the Human Mind (Condorcet (1795)). Malthus was highly critical of Condorcet’s notion of unlimited progress. Malthus draws a distinction between unlimited progress and progress with indefinite limits. Considering contests for growing carnations, Malthus observes that while we cannot say definitively what the maximum size of a carnation might be, it is obvious that carnations cannot be arbitrarily large. If Malthus could respond to Julian Simon, he might say that while we cannot definitively determine the limits in the availability of natural resources, they are clearly not infinite (though, as noted above, Malthus seems to side with Simon when discussing non-food commodities).

Malthus observes that the fundamental drive toward population growth is the passion between the sexes, toward the elimination of which there had been no progress, insofar as one would consider such an outcome to be progress. Although Malthus anticipates the demographic transition to an extent, I find that, despite some halting efforts, he is hard-pressed to explain this trend, and it is not even clear to me whether he would regard such a trend as “progress”.

In response to William Godwin’s On Avarice and Profusion (Godwin (1797)), Malthus is derisive of Godwin’s explanation of social problems as results of flawed and fixable human institutions. Instead, Malthus is clear that conflict, and thus evils, between people is the result of population pressures, which as we’ve established, Malthus considers to be inevitable. Thus evil is an inherent aspect of a finite world with irresistible attraction between the sexes. It is this view that places Malthus squarely in the small-c conservative camp.

Malthus is particularly concerns that Godwin’s alleged utopia, without financial pressures and with free love, would result in massive population growth. But relative to the late 18th century, the modern world features much greater affluence and much more acceptance of untraditional love arrangements. Nevertheless, birth rates are much lower, not higher, than in Malthus’ day.

The Meaning of It

The final two chapters of the essay draw upon Malthus’ religious belief. Malthus takes the view that exertion and suffering are necessary for the spiritual progress of humans, and the ideal society would present neither too great of comfort nor too great of deprivation. Thus utopian, post-scarcity arrangements such as that proposed by Godwin are not only unworkable in Malthus’ mind, but also highly undesirable.

Malthus describes population pressures in the world as part of the providential plan for the salvation of mankind. He does not regard it as a problem that either can be fixed or should be attempted to be fixed. This may also explain why there is no discussion of population control.

Elsewhere in the essay, Malthus is derisive of Condorcet’s notion of indefinite life extension. He does not consider this to be possible, and if it were possible, it would add to already great population pressures. But even more serious is that, Malthus assesses, an indefinitely extended life would not be one worth living, especially in consideration of the life in the hereafter.

Conclusion

I found Malthus’ essay to be a much more interesting read than I expected, and there were several arguments that surprised me.

Nevertheless, despite his rather contorted attempts to explain European demographic trends with the framework of “misery and vice”, it is clear that the framework is simply inadequate. Two centuries of falling birth rates around the world, especially in wealthy countries, have made this even more clear. Malthus’ essay is important as an historical work, especially given his great influence over ecologic movements of the 20th and 21st centuries, but as a contribution to demography, the essay has no value.

Quick Hits

There is so much more that I wanted to say about Jimmy Carter last week, but limitations of time and length prevented me from doing so. One particular disappointment is that I devoted almost no attention to energy policy, given that Carter’s administration is, for better or worse, the most consequential in American history on that subject. For that, I recommend Matthew Wald’s, of the Breakthrough Institute, piece on Carter’s nuclear policy. Wald finds Carter’s stance toward nuclear power to be highly deficient. One interesting point is that pundits often decry the lack of technical expertise in democratic politics, with an overabundance of lawyers and other such professions. Carter was a nuclear engineer, as much technical expertise as one can hope for, and this did not prevent him from making several major bad policy decisions on nuclear power.

There has been a campaign against seed oils for the last several years, but it seems like in the last couple of months, it has attained a heightened level of prominence, with the fast causal restaurant chain Sweetgreen offering seed oil-free items. Laura Williamson of the American Heart Association explains why seed oils present little reason for fear.

For the technical minded, Bronwyn Hall discussed some of the measurement challenges around the private and social returns to research and development (Hall (1996)). It is obvious (?) that research and development is critical for progress in standards of living, but it is not at all obvious how to measure that benefit and make well-informed R&D decisions.