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Malthus vs. Malthusian Population Scares

This post is by Adam Martin, a post-doctoral fellow at DRI.

The laws of economics are more powerful than the laws of physics. I once saw Deirdre McCloskey illustrate this by placing a $100 bill on the table. The laws of physics, she reminded the class, dictate that an object at rest tends to stay at rest. Economics tells us that errant $100 bills laying out in the open do not remain unattended for long. She assured the students that, were she to leave the room for several hours, economics would better predict Mr. Franklin’s fate.

But how do the laws of economics fare against a tougher opponent: the laws of sexual attraction? Against them, economists–especially those march under the Malthusian banner–have been willing to cede more ground. Everyone knows, after all, that Malthus judged the “passions between the sexes” as both universal and powerful. Everyone knows that this passion leads to “geometrical” increases in population that inexorably outpace “arithmetical” increases in food. Everyone knows this is why economics is called the “dismal science.” But what everyone “knows” is dead wrong.


This is not another argument about how ol’ Tom-Bob got it all wrong. No, the problem with Malthus–a problem for both his self-proclaimed friends and foes–is that he we wasn’t a Malthusian.
Ross Emmett offers a detailed and trenchant analysis. Malthus was not arguing in a vacuum. He was responding to William Godwin’s proposal to overthrow basic social institutions like private property and the family.  In a free love-fest where no one is responsible for the offspring resultant from their passions, Malthus argued, population growth would run amok. If individuals don’t bear the cost of procreation, they will procreate too much. If they do bear costs of offspring, “preventative checks” such as birth control and delayed marriage will make population self-regulating. In his own words:  “Impelled to the increase of his species by an equally powerful instinct, reason interrupts his career, and asks him whether he may not bring beings into the world, for whom he cannot provide the means of subsistence.” (An Essay on the Principle of Population, Chapter II). Reproductive choices respond to incentives. The laws of economics are more powerful than the laws of attraction.

by John Odell, 2001

by John Odell, 2001

Note that Malthus does not say that the incentives for procreation are automatically aligned with the common interest. If individuals do not bear the full costs of their offspring, such as any effects of Junior on the environment, they may make irresponsible decisions. But parents are no more socially responsible if they fail to account for the benefits their children will generate for others (such as new ideas on technology). What matters is that, when discussing population, we do not forget the basic lessons of economics. A top-down perspective on population that treats individuals like mindless lemmings will panic: “Unless we reduce the human population humanely through family planning, nature will do it for us through violence, epidemics or starvation.”

Malthus gets right what both his followers and his more technocratic critics get wrong: the institutions within which individuals make reproductive decisions matter. The way to increase GDP per capita is not to cut the denominator. And while today’s scare tactics (Mali is “really in for a Malthusian disaster,”) and recommendations to stop having babies are not as monstrous as those of yesteryear, we should be wary of those who would intrude on one of the most personal and sacred choices individuals confront – whether to have a child. Nor is population sustainability a mere horse race between libido and technology. Consistent with the approach of classical economists, Malthus treats human nature as constant. Different institutions drive differences in fertility outcomes. In this we should all be Malthusians.

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  1. E Aboyeji wrote:

    God love you men. Wonderful post!

    Posted December 11, 2009 at 12:20 am | Permalink
  2. Tord Steiro wrote:

    suddenly, it’s all about population. I just got Oxfam’s Duncan Green into my reader:

    And, as Green points out, in certain places of the world, like South Korea, the problem is not that parents do not have to think about the cost of raising children, but rather the opposite. Many developed societies are currently facing the opposite demographic crisis, that of falling fertility and raising age. Parents are perhaps facing too high private costs relative to the value of children to society as a whole?

    Posted December 11, 2009 at 5:05 am | Permalink
  3. patrick wrote:

    I believe that an object at rest will remain at rest UNLESS acted upon by an unbalanced forced. Perhaps humans, being the avaricious creatures they are, are rather inclined to acting as that unbalanced force. If these conditions hold true perhaps these laws of economics play a part in the overarching laws of physics.

    Posted December 11, 2009 at 11:48 am | Permalink
  4. Raphael wrote:

    So what should the policy maker or field practitioner do? These posts are all great food for thought but they always leaves me asking, what next?

    We know that in all known historical cases, the demographic transition occurs as countries develop/grow. So maybe the incentives (cost per child) automatically change and people have fewer kids? But where does that leave me as a micro-level practitioner in the field? How do I get a mother in Ethiopia or Nigeria to “bear the cost” of another child so that she takes “preventive” measures? Do I do health education on the benefits to the mother of delaying marriage and child-birth? Do I build the capacity of the health post to provide quality family planning services? Or do I just wait for the incentives to kick in at some macro level? Or do I advocate for certain institutional changes that will, in turn, change the incentives? And if so, what should I advocate? Shouldn’t this be a bottom up process anyway?

    Critiques are great! But maybe we should also have potential prescriptions useful for those of us that need to design programs and develop policy.

    Posted December 11, 2009 at 3:10 pm | Permalink
  5. E Aboyeji wrote:


    Or you can just end the population baiting and focus on economic growth. Apparently, population growth is good for economic growth.

    Posted December 11, 2009 at 4:36 pm | Permalink
  6. Raphael wrote:

    E Aboyeji. Population growth is good for econ growth? Is that another regression?

    Posted December 11, 2009 at 8:39 pm | Permalink
  7. Lukas Schlögl wrote:

    “The way to increase GDP per capita is not to cut the denominator.”

    hmm . . . that goes against my calculative intuition.

    Posted December 13, 2009 at 5:55 am | Permalink
  8. E Aboyeji wrote:


    Ofocurse! Economic growth, as defined by a constant rise in the GNP, is largely dependent on population growth. It is something I am working on. You would be surprised at the trends we are witnessing.

    Posted December 13, 2009 at 4:33 pm | Permalink
  9. D. Watson wrote:

    Patrick – I was thinking the same thing. Here, then, institutions matter in physics.

    Posted December 15, 2009 at 11:01 am | Permalink
  10. Marcel E. Velásquez wrote:

    I remember many years ago in Peru, giving a college-level class on Peruvian society to well-off kids, the class consensus was that poor people irresponsibly had too many children regardless of whether the families would be able to take good care of them or not (they assumed that, on average, they wouldn’t). I was a little irritated, I must confess, as it was framed in a very moralistic terms.
    I tried explaining how in the traditional rural Andes, wealth is a function of labor, and the larger your family, the more people you can count on to harvest your land and build a house (actually, the Quechua word for poor, “waxcha” or “waqcha” also means orphan). Moreover, high mortality rates among poor rural indigenous people and a lack of meaningful social insurance mechanisms, make having a larger family the only retirement account worth holding.
    Even when moving into the cities, such economic strategies, embedded within cultural costumes, won’t change overnight. Especially since there is still a case to be argued for having a larger family if the educative system is so bad that the marginal benefits of additional school years don’t increase productivity enough to compensate for the opportunity costs.
    I’m describing, of course a worse case scenario, which may vary for different families, and there are now many more good incentives for families to have fewer kids and focus their attention and resources on them. However, this decision is still dependent on a meaningful educative system that effectively raises productivity, chances of them getting into advanced studies, a reduction in mortality rates, etc.

    Posted December 16, 2009 at 6:11 pm | Permalink

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