Saturday, January 8, 2011

The Malthus PR Problem

I was thinking the other day in the midst of the DeLong-Boudreaux tempest in a teapot that the public image of Malthus is very unfortunate. If the broader public knows him at all they know him as a depressing guy that foolishly picked two growth rates (for humans and for food) that put the human race on a collision course with disaster. It was, of course, an equilibrium theory of sorts. A subsistence equilibrium, but an equilibrium nonetheless. And yet it is also associated with impending future doomsdays. That's a little odd isn't it? Malthus was talking about the way humans have lived all throughout history - constant pressures that drive us towards a subsistence equilibrium if we ever get into disequilibrium. And as Brad DeLong and Paul Krugman have pointed out in the past - he was right in describing history up until the industrial revolution!

What's more is that Malthus played an instrumental role in inspiring Charles Darwin's thinking on natural selection. Now, in some corners of America today perhaps that's another mark against him, but I think that's fairly substantial!

What's also ironic is that while his essay on population had perhaps the widest impact through its influence on Darwin, it was his work on political economy that has probably had the most impact on economics. Malthus was the premier proto-Keynesian. I worry sometimes that Keynesianism suffers from its associaiton with Malthus because people irresponsibly brand environmental doomsday prophets as "Malthusian".

I'm not sure where to go with that of course. It's just one of those instances of bad PR that the victim - who is long dead - can't do anything about.


  1. Krugman's claims that many primitive societies eventually reach some stage of bare minimum subsistence is a little one-sided.

    Levels of subsistence can vary dramatically across civilizations across history in regions with large populations and small. What it depends on is how much division of labour and specialization is possible through the availability of easy routes for movement of food and other supplies, areas where large number of people can concentrate, and the ease provided by the climate. France had a population larger than that of Russia, but still a better fed population in the pre-industrial days, even in a smaller geographic area.

    Also - it is quite interesting, for example, that England in the peak era of raw feudalism did not have the growth-stunted, toothless, bent peasants we expected, but rather physically strong men and women with heights reaching 6 feet. Because bone density also increases with muscle size, medieval era men showed high bone density in their right shoulder. This fact is significant, because we see from the now famously publicized Towton graves that entire skulls of soldiers have been cleaved and bisected. Meaning that an ordinary English feudal soldier possessed enough strength in his right arm to have his sword cut through a helmet and into a skull and through it.

    On the other hand, Romans even with an empire large enough to support vast stretches of farmland had people of very short height and a poor diet. Food production was one thing, but transporting food by land has proven harder than transporting by water. Much easier in England with many rivers and a bending coastline.

  2. Mises is actually a Malthusian. He just takes a more classical liberal approach and says that our ability to continue growing (population wise) is due to economic growth, and if there are sufficient restraints on capital accumulation and economic growth then we will face population problems. But, he says that Malthus' law is biologically undeniable.

  3. ^^^
    Doesn't that make overpopulation a tautology? If overpopulation is a situation of people being greater in number with respect to their resources, then people with few resources are by definition overpopulated.

    Meaning that even people in scantily populated Sudan are overpopulated, because they have little food even with a small population.

    A population problem IS a capital accumulation problem, and it's not that one leads to the other, right?

  4. Prateek - did you see the recent research suggesting that medieval English had something like double the average income we thought they did - the equivalent of something like a thousand of todays dollars when they used to think it was only several hundred. I don't know they details of how they worked that out, but it should be easy to find - only came out in the last couple months.

    Jonathan - so Mises's view that wages will be driven to a subsistence level if capital accumulation stops? The simple point that populations are always constrained by the resources available is clearly a true claim in Malthus. What I think has been effectively repealed is the idea that subsistence is going to be the constraining factor on the human population. It's been a while since I've read the essay though (and even when we read it in school we never covered it in its entirety) - I do remember he spent time discussing voluntary restraint as well, which obviously is more important these days.

  5. "If overpopulation is a situation of people being greater in number with respect to their resources, then people with few resources are by definition overpopulated."

    I'm not sure this makes sense without an important qualification. That qualification is that the resources available must not be able to support that population size (all resources are scarce, no matter the population size).

  6. Daniel,

    Both Mises and Reisman write that Malthus is correct, regarding wages, if capital accumulation and technological development (the latter of which both regard as a corollary of the former) doesn't increase productivity. It's just a question of diminishing marginal returns applied to the human population.

    I think there might be a natural tendency to cut population growth at that point of substance though, given that not until the last two hundred years did we have exponential human growth. For most of history, population growth has hit asymptotes, and risen only as standards of living rise. It probably has something to do with wealth maintenance down on the family level.


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