All Commentary
Thursday, April 18, 2013

What’s Right with Malthus?

If . . . we come to the conclusion, not to interfere in any respect, but to leave every man to his own free choice, and responsible only to God for the evil he does . . . this is all I contend for.

   —Thomas Robert Malthus

I am constantly surprised that defenders of liberty and free markets love to bash Thomas Robert Malthus.

Maybe I shouldn’t be, but consider this: Robert Malthus (his friends called him “Bob”) was one of the primary interpreters of Adam Smith for the generation after Smith. Indeed, a lot of people who pick on “Thomas” Malthus get Bob Malthus wrong.

That’s not to say that Malthus was right about everything. But even more than Smith’s, Malthus’s economics built upon the idea that all humans similarly respond to incentives, and he thereby rejected the idea of natural hierarchy. Writing in a country that had excessive restrictions on labor markets—take a look at the poor laws—Malthus was an advocate of free labor markets. And Malthus argued that private property rights, free markets, and an institution that would ensure that both parents were financially responsible for the children they bore (that is, marriage) were essential features of an advanced civilization.

“Wait a minute,” you may be thinking. “Are we talking about the Malthus who claimed back in 1798 in his book An Essay on the Principle of Population that population growth would decrease per capita well-being? Isn’t this the guy who argued that the combination of population growth and natural resource scarcity would create catastrophic consequences, including disease, starvation, and war, for much of the human race? And didn’t he miss the benefits of entrepreneurship and innovation, blinded as he was by the fallacy of land scarcity?”

That Malthus—let’s call this one “Tom”—is more a creature of the ideological opponents of markets than of Malthus’s own writings. So maybe we should revisit Malthus and see what he actually said.

It all begins with a thought experiment: What would happen to human population in the absence of any institutions?

The answer is the population principle, which is the only thing most people know about Malthus. And it’s largely correct. In the absence of institutions, humans are reduced to their biological basics. Like animals, humans share the necessity to eat and the passions that lead to procreation. To eat, humans must produce food. To procreate, humans must have sex. If there are no institutions, human population will behave like any animal population and increase to the limit of its ecology’s carrying capacity.

The biological model is simplistic; it treats humans as mere biological agents. It is this biological model that produces all the results people usually associate with Malthus’s name. And it’s not very far off from people’s conditions when their institutions have suddenly been disrupted by things like conquest, revolution, or war. (Consider the dual problems of war and drought that resulted in famine for Ethiopians in 1983–85, for example.)

But for Bob Malthus, the biological model is only a starting point. The model set up his next concern: the incentives created by different institutional rules for families’ fertility choices (in Malthus’s terms: the decision to delay marriage). The comparative institutional analysis that emerged from his further investigation became the basis for his defense of the institutional framework of a free society.

But to get there, Malthus needed a more complex model of the human being, one that viewed us as more than biological agents.

His more complex model included two additional things.

The first was human reason and foresight. (Darwin’s model of natural selection actually came to him when he asked, while reading Malthus, what the biological response to the lack of foresight and reason would be.) Malthus asked, what happens when we recognize that humans have the capacity to anticipate the future and to respond to it? His answer was that individuals prudentially make changes in their choices in order to respond to potential opportunities and threats.

The second thing Malthus introduced was a form of contractarianism and the idea of institutional incentives. When we recognize that humans can contract with others to create rules that will structure our future options, then we are building social institutions that incentivize individual actions.

Malthus first employs both of his models in his criticism of William Godwin’s Political Justice, at the end of his original Essay. Using the biological model, Malthus shows that Godwin’s call to eliminate all institutions would result in rapid population growth, creating the threat of a population “bomb.” But then he stops short of reducing humanity to Hobbes’s tragedy of the war of all against all. (Garrett Hardin went further than Malthus would in his “tragedy of the commons” article, which has had such an influence on neo-Malthusians.) Why does Malthus not draw the obvious neo-Malthusian conclusion? Because he begins to employ his complex model instead.

Seeing the prospect of falling into a Hobbesian state of nature, people would rather “hold a convention” and establish property rights. And then, he argues, they would fashion a rule or institution (call it “marriage”) that would require parents—especially fathers—to be financially responsible for their children. These institutional moves would allow society to create a sustainable future.

The institutional considerations of his more complex theory really come out, however, in subsequent editions of the Essay. In these editions, Malthus engages in a nascent form of empirical institutional analysis. Between his own travels and traveler reports from around the world, he assembles a comparative study of how different institutional settings handle population growth. His hypothesis is simple: Nations with civilized institutions will depend less on the positive checks on population growth because their citizens are provided with clear signals that allow prudential decisions regarding the delay of marriage. What he found was that in societies with private property rights, markets, and incentives that encourage responsible fertility choices (what he called marriage), the positive checks of disease and starvation never come into play, while in societies without those institutions, the positive checks operate in full force.

It turns out the mainstream view of Tom (as opposed to the real “Bob”) was first created by opponents of markets, sustained throughout the nineteenth century by lovers of hierarchy, and resuscitated in the twentieth century by environmentalists committed to the view that there are natural limits to economic growth. These environmentalists picked out the bits they liked and scrapped the rest, as it suited their agendas.

But Bob Malthus thought institutions mattered. For Malthus, the institutions of a free society mattered for prudential fertility choices, as well as for human flourishing.


  • Ross B. Emmett is a professor in James Madison College at Michigan State University (MSU) and co-director of the college’s Michigan Center for Innovation & Economic Prosperity.