Population figures for all countries and many regions of the planet for the past fifty years can be found through the Population Database provided by the United Nations Population Division.
In the last Teacher's Corner, we saw how badly Malthus' arguments in An Essay on the Principle of Population (1826, first pub. 1798), have been misunderstood and misrepresented by detractors from his own day and ours. We also saw that his predictions concerning how British population and production would grow in the centuries after he wrote were not nearly as gloomy as both detractors and supporters claimed. This time, we will note that Malthus' predictions, while not pessimistic, were far short of the actual experience, and offer some thoughts as to why this was. Also, we will briefly discuss more recent examples of writers who, like Malthus, made controversial claims about population pressures on resources, and how, also like Malthus, they were mistreated by critics.
Malthus' Argument and Predictions
Malthus wrote in Book I, Chapter 1 of his Essay that in newly settled areas like the United States in the 17th and 18th centuries, where there were vast amounts of uncultivated land readily available, food production and therefore population could and did grow much faster than arithmetically.
In the previous column, we outlined Malthus' main argument, that if there were no impediments or checks to population growth, then population would grow exponentially (that is, at an ever-increasing rate). The key phrase in the argument is if there were no impediments or checks to population growth. Malthus recognized that impediments do exist and that people take them into account when they make decisions regarding procreation. In particular, individuals look at the resources they have available when they think about having children. Malthus believed that in most cases food production, the "means of subsistence" to use his phrase, can at best grow arithmetically (at a constant rate). People therefore make conscious choices not to have as many children as is biologically possible, but rather limit the number of children they have according to how much food they have.
There are two possible responses individuals can make when more food becomes available. Think of a fictional family of four, two parents and two children. Let's say that each of them consumes 100 bushels of food a year, and that our family is able to acquire (either by farming themselves or working some other jobs and buying it with their wages) 400 bushels of food a year, which is just enough. Now consider that, whether through improvements in farming or higher wages, our family becomes able to acquire an extra 100 bushels a year, for 500 total.
The first response the parents might have is that with the extra food they can afford to have another child and still have the same amount of food available to each family member. If many families had this response to a rise in the food available, then population would rise and consumption per person would stay the same.
The second possible response of the parents would be to realize that if they keep the size of the family at four people, then with the extra food they could each have 125 (500/4) bushels per year. Population in this case would remain the same, but consumption per person would rise.
Malthus described the checks to population growth that each class of English society imposed on itself in the first seven paragraphs of Book II, Chapter 8 of his Essay.
Malthus believed that the people in each class of society had a certain consumption level to which they are accustomed (like the 100 bushels a year in the example, only he conceived it more as a general standard of living or lifestyle, not a specific quantity of food or income). So long as having an additional child would not push a family below that threshold, he argued that individuals would generally choose to have more children. In other words, the first response would be the one chosen by most families. For people in the lower classes of society, whose customary consumption level was at or near the starvation point, this implied that they would continue having children up to the limits of the food available to them. As Malthus phrased it in paragraph 15 of Book III, Chapter 13 of his Essay that "the tendency in population fully to keep pace with the means of subsistence must in general prevent the increase of these means from having a great and permanent effect in improving the condition of the poor."
For a graph showing the astounding growth in world population from 1750 to 2150 (projected), go to the Population Reference Bureau website. The accompanying essay provides a good summary of population growth over the last two centuries, but also contains the type of misunderstanding about Malthus' work that was discussed in the previous Teacher's Corner.
But Malthus was hopeful about the future improvement of the condition of the poor. He argued that with proper instruction, the lower classes (and presumably other classes as well, although Malthus focused on the poor) could come to understand that by adopting the second response and choosing to have fewer children even when resources expand, they had the power to elevate their own circumstances and establish for themselves a higher customary consumption level, a higher standard of living. As we noted at the end of the previous column, Malthus wrote in paragraph 2 of Book IV, Chapter 4, that if such instruction were to occur,
I can easily conceive that this country, with a proper direction of the national industry, might, in the course of some centuries, contain two or three times its present population, and yet every man in the kingdom be much better fed and clothed than he is at present.
Malthus therefore recognized that the human condition could and likely would improve, contrary to the popular misinterpretation of his Essay. However, the actual population growth and material improvement that occurred was greater and more rapid that anything Malthus suggested. Looking at these figures compiled for a course on Western Civilization at the University of Chicago, we see that the population in Great Britain went from about 10,500,000 in 1800 to about 40,800,000 in 1910. Currently, British population is about 60,000,000, representing almost a sixfold increase in two hundred years.1
Turning to how much better off British citizens have become, a recent article by Roderick Floud and Bernard Harris titled "Health, Height and Welfare: Britain 1700-1980"2 shows that per capita GDP for Great Britain rose about 710% between 1801 and 1978. Although Malthus' phrase "much better fed and clothed" is vague, nothing in the Essay indicates an awareness of the potential for such a dramatic increase.
For example, Frederic Bastiat, who defended Malthus in Chapter 16 of Economic Harmonies (1996, first pub. 1850), criticized Malthus for being too pessimistic and laid out a far more optimistic vision of humanity's future in the last part of the same chapter, starting on paragraph 89.
It is a bit unfair to compare two hundred years' worth of actual statistics to Malthus' rough speculation, especially given that his speculation pointed in the correct direction, that the relative proportions of growth in population and in production would combine to improve human welfare over time. Still, it is worth noting that even though Malthus' predictions were not as gloomy as his critics and supporters believed, at least one other economist of the time was far more optimistic about progress than he was. Did Malthus misjudge some factor that caused him to seriously underestimate the massive expansion of population and resources that was to occur?
What Malthus May Have Misjudged
The case can be made that Malthus underestimated the impact an increase in manufacturing production would have on the human condition relative to the impact of an increase in agricultural production. Malthus described his views on the way increasing wealth affects the condition of the poor in Book III, Chapter 13 of his Essay.
In paragraphs 4 and 5, he takes issue with an assertion about a society's wealth made by Adam Smith in Book I, Chapter VIII of An Inquiry into the Nature and Causes of the Wealth of Nations (1904, first pub. 1776):
Adam Smith defines the wealth of a state to be the annual produce of its land and labour. This definition evidently includes manufactured produce as well as the produce of the land. Now, upon the supposition that a nation, from peculiar situation and circumstances, was unable to procure an additional quantity of food, it is obvious that the produce of its labour would not necessarily come to a stand, although the produce of its land or its power of importing corn were incapable of further increase. If the materials of manufactures could be obtained either at home or from abroad, improved skill and machinery might work them up to a greatly increased amount with the same number of hands, and even the number of hands might be considerably increased by an increased taste for manufactures, compared with war and menial service, and by the employment consequently of a greater proportion of the whole population in manufacturing and commercial labour.
That such a case does not frequently occur will be most readily allowed. It is not only however possible, but forms the specific limit to the increase of population in the natural progress of cultivation, with which limit, the limit to the further progress of wealth is obviously not contemporary. But though cases of this kind do not often occur, because these limits are seldom reached; yet approximations to them are constantly taking place, and in the usual progress of improvement the increase of wealth and capital is rarely accompanied with a proportionately increased power of supporting an additional number of labourers.
Wealth, broadly speaking, can be thought of as a person's or society's ability to acquire through exchange the goods and services the person or society wants. Apart from the direct benefits that manufactured goods like air conditioners, cars, and medical machines provide (a point that Malthus acknowledged in paragraph 15), manufactured goods are a part of a society's wealth because they can be traded for other things that people want, including food. So long as there is nothing hindering exchanges of one type of goods for another, there is no reason why wealth derived from manufacturing production should contribute less to the well-being of a society than wealth derived from agriculture.
In the first paragraph of the passage above, Malthus was pointing out that if something does hinder the ability of a society to either grow more food or exchange manufactured goods for food (the "peculiar situation and circumstances"), then even though the total production of a society rises when manufacturing production rises, the condition of the society's people as measured by the level of the means of subsistence may not change. In other words, Malthus criticized Smith's definition of wealth as being strictly concerned with the quantity of total production, without taking into account how exchangeable different types of production might be.
The second paragraph argues that even though it rarely happens that societies are completely unable to produce or procure more food, it often can be difficult for them to do so. As a result, the ability to exchange manufactured goods for food can be reduced. Because Malthus believed that it often was the case that there were binding constraints on the amount of food a society could acquire, he concluded in paragraph 14 that "It must be allowed then, that the funds for the maintenance of labour do not necessarily increase with the increase of wealth, and very rarely increase in proportion to it."
The idea that there are limits, at least in the short run, on the amount of food that a society can produce on its own is a major component of Malthus' main argument, so we need not address it here. For there to be hindrances to the exchange of manufactured goods for agricultural goods, it would also need to be difficult for a society to import food from another society. Malthus took up this point in paragraph 12:
If trade and foreign commerce were held in great honour in China, it is evident that, from the great number of her labourers and the cheapness of her labour, she might work up manufactures for foreign sale to a great amount. It is equally evident that, from the great bulk of provisions and the prodigious extent of her inland territory, she could not in return import such a quantity as would be any sensible addition to her means of subsistence. Her immense amount of manufactures, therefore, she would either consume at home, or exchange for luxuries collected from all parts of the world.
Thus, Malthus did not deny that in theory manufactured goods could be exported to increase the amount of food available in China and improve the condition of its people. He simply called into question the possibility, as a practical matter, of importing the large amount of food that would be required and distributing it over China's vast area.
This brings us to Malthus' real area of misjudgment. Malthus had no objection to the idea that wealth derived from manufacturing production could, subject to certain hindrances, be exchanged to increase the amount of food available. He seems only to have misjudged the degree to which those hindrances would be reduced over time. He did not recognize the extraordinary advances that were to come in food production, storage and transportation. However, he should probably be forgiven his misjudgment because the advancements that actually occurred were more dramatic than any the world had seen before.
American economist Julian Simon, in his book The Ultimate Resource 2 (1996), documented changes in farm labor productivities for the United States from 1800 to 1967.3 From 1800 until about the middle third of the twentieth century, they followed exactly the sort of linear or arithmetic growth that Malthus described, the indices of productivity rising from 100 in 1800 to about 300 in 1940. After that, however, they started to skyrocket, more than doubling in almost every decade since then. This unprecedented explosion in productivity, combined with the accumulation of technological advances that the resulting wealth made possible, was a crucial driver of the population and income growth that occurred. Nothing like that rise in productivity had been seen in human history, so it is hard to criticize Malthus for not anticipating it.
Attacks on Other Authors
Despite this shortcoming in his predictive ability, Malthus' main argument, that population is kept in check through rational, conscious decisions made by individuals, remains intact. As such, he did not deserve the type of abuse described in the previous Teacher's Corner. Nor was he the only writer who found himself on the receiving end of bitter attacks after writing controversial things about population and resource management.
In The Ultimate Resource 2 as well as several other books, Julian Simon, who was introduced above, documented how many of the environmental problems that are reported in the global media are actually getting better, not worse, over time, and that the improvements are largely the result of individual actions rather than collective actions by governments or other organizations. As a result of flying in the face of the conventional wisdom about environmental issues, Simon was widely derided as dishonest or ignorant concerning the issues on which he wrote. The Ultimate Resource 2, written as a follow-up to The Ultimate Resource (1981), contained a section detailing some of the attacks directed at him over the previous years. The level of enmity contained in many of these attacks is portrayed in this one from page 603, written by Robert May, a former head of the zoology department at Harvard and chief scientific adviser to the British government, concerns Simon and a co-author's treatment of extinction data:
It is very difficult for me to see how any serious and honest person, acting in good faith, could do something so stupid as to take documented extinction figures which pertain essentially to vertebrates and treat them as if they applied to all metazoans.... Sadly, I conclude that what we are dealing with here is not an honest pursuit of intellectual understanding, but rather with some other agenda (or possibly with stark stupidity, or even both).
(Simon subsequently explained that he had never made estimates of the overall extinction rate, an assertion borne out by chapter 31 of The Ultimate Resource 2.)
Another nasty characterization came from Paul Ehrlich, a professor of population studies at Stanford, prominent environmental advocate, and longtime vocal critic of Simon. Simon quoted Ehrlich on page 602 as saying
It's as if Julian Simon were saying that we have a geocentric universe at the same time NASA's saying the earth rotates around the sun. There's no reconciling these views. When you launch a space shuttle you don't trot out the flat-earthers to be commentators. They're outside the bounds of what ought to be discourse in the media. In the field of ecology, Simon is the absolute equivalent of the flat-earthers.
It is worth noting that Ehrlich and two of his colleagues famously took up Simon's open wager that over a ten-year period the inflation-adjusted prices of five metals (selected by Ehrlich and his colleagues) would decline, implying that those resources had become less scarce over that decade. The inflation-adjusted prices all fell, and Ehrlich and his colleagues lost.4]
Simon also explained that the amount of substantive negative comments he got was quite small relative to the amount of bitter, ad hominem attacks he received against his academic integrity, against political motives that critics (inaccurately) ascribed to him, and against him personally.
More recently, Danish statistics professor Bjorn Lomborg wrote The Skeptical Environmentalist (2001), a book with much the same purpose as Simon's, to compile and present the best scientific data currently available on a variety of environmental issues.5 Although a self-described "old left-wing Greenpeace member" who initially undertook the work thinking he would find Simon was wrong, Lomborg found that in most respects, the environment is indeed getting better.
Like Simon, Lomborg too was ridiculed and attacked by other scientists and commentators. A series of often polemic critiques against his work, written by scientists with histories of environmental activism, appeared in Scientific American under the heading "Science defends itself against the Skeptical Environmentalist."6The Economist reported that "Mr. Lomborg is being called a liar, fraud, and worse. People are refusing to share a platform with him. He turns up in Oxford to talk about his book, and the author (it is claimed) of a forthcoming study on climate change throws a pie in his face."7 On the subject extinction rates, two environmental researchers writing a review of Lomborg's book in the November 8, 2001 issue of Nature compared Lomborg's methodology to that of gay-bashers and Holocaust deniers (the review and Lomborg's response can be found in a pdf on Lomborg's home page):
The text employs the strategy of those who, for example, argue that gay men aren't dying of AIDS, that Jews weren't singled out by the Nazis for extermination, and so on. "Name those who have died!" demands a hypothetical critic, who then scorns the discrepancy between those few we know by name and the unnamed millions we infer.
What accounts for the bitterness shown by attackers of Simon, Lomborg, and Malthus? It seems especially puzzling when one notes that Malthus on the one hand and Simon and Lomborg on the other were apparently on opposite sides of the question of whether there exists the potential for serious adverse effects due to population growth and pressure on natural resources.
There is a consistency among these attackers. The most hostile critics against all three writers called for collective action to solve the problems they believed Malthus, Simon and Lomborg were each denying. William Godwin, the critic of Malthus who featured prominently in the previous column, called for the complete revamping of human institutions, which he argued were the cause of all impediments to mankind's progress. The environmental activists and groups that reacted so unkindly to Simon and Lomborg often advocate bans on certain types of production, energy, or activity, and want those bans to be enforced by governments or even international bodies like the United Nations.
Malthus, Simon and Lomborg may have had different answers to questions of population and resources, but all of their answers placed great emphasis on the role of the individual. Malthus argued that the most important factors preventing more widespread starvation from occurring and allowing for the improvement of the condition of the poor were individuals deciding whether it was in their own self-interest and the interest of their families to have more children. Simon extolled individuals following their own private incentives as the ultimate resource which would prevent shortages of other resources. Even Lomborg, who did argue for collective approaches to address some environmental issues, made as his main theme the need for more widespread knowledge of the best environmental evidence available so that individuals can better prioritize environmental, economic, and social issues within the democratic process.
Exactly why those who call for more emphasis to be placed on the individual when it comes to population pressures and natural resources should be singled out for bitter and abusive attacks is not clear to me. It is clear, however, that Malthus, Simon and Lomborg were all mistreated at the hands of critics who believed in the need for collective solutions. Whether this common thread is merely a coincidence or indicative of a more general feature of the debate between individualists and collectivists is an interesting point for debate, but is beyond the scope of this essay.
Population figures for all countries and many regions of the planet for the past fifty years can be found through the Population Database provided by the United Nations Population Division.
Roderick Floud and Bernard Harris, NBER paper, available online as a pdf at "Health, Height and Welfare: Britain 1700-1980", page 55.
Julian Simon, The Ultimate Resource 2, Princeton: Princeton University Press, 1996, page 99.
Simon, pages 35-36.
Bjorn Lomborg, The Skeptical Environmentalist, New York: Cambridge University Press, 2001.
Scientific American, Volume 286, Number 1, January 2002.
The Economist, February 2, 2002.