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Diamond in Rough

In this New York Times op-ed, Jared Diamond summarizes the thesis of his new book, Collapse. A favorable review of this book is this one, in The New Yorker, by Malcolm Gladwell. (Thanks to Arnold Kling for this reference, and for bringing my attention to Matt Yglesias’s rebuttal of one of Diamond’s important empirical claims.)

I’ve not read Diamond’s book, so I can’t comment on it. But I did read his lengthy op-ed, and find it to be surprisingly weak.

Diamond’s thesis (judging from his op-ed) seems to be built on the tragedy of the commons. But it’s not. And the reason that it’s not stems from the larger problem I have with his thesis.

First, though, I register my smaller complaint: Diamond glibly treats too many of his suppositions as undisputed facts. In particular, he supposes that population growth is necessarily a problem, and that humankind is running out of resources.

These suppositions aren’t ridiculous, and probably most folks believe them to be true (which is why Diamond can simply suppose them to be true). But nor are these suppositions unchallenged – with data – by serious scholars. Diamond (again, in his op-ed; I don’t know about his book) simply ignores these challenges.

The collections of data by Julian Simon, here and here, and by Bjorn Lomborg, here, are the most relevant challenges to the supposition that population growth is usually a curse and that resources are becoming more and more scarce. While I find these data to be compelling, it’s possible that they – or their interpretations by Simon and Lomborg (and me) – are wrong or misleading. But Diamond writes as if Simon’s and Lomborg’s research doesn’t exist. In his op-ed of nearly 2,500 words, Diamond doesn’t even acknowledge the existence of serious empirical research that challenges his key suppositions about the condition of today’s world.

The larger problem with Diamond’s thesis is revealed in his book’s subtitle: How Societies Choose or Fail to Succeed. He anthropomorphizes human collectives. He talks as if we – or some variant of "we" – have a collective mind that makes decisions for us as a whole. Consider:

There are many reasons why past societies made bad decisions, and thereby failed to solve or even to perceive the problems that would eventually destroy them. One reason involves conflicts of interest, whereby one group within a society (for instance, the pig farmers who caused the worst erosion in medieval Greenland and Iceland) can profit by engaging in practices that damage the rest of society. Another is the pursuit of short-term gains at the expense of long-term survival, as when fishermen overfish the stocks on which their livelihoods ultimately depend.

This passage cries out for good tragedy-of-the-commons analysis. But it never gets such analysis. Instead, while sensing that something like what economists call negative externalities are in play – that is, while sensing that some institutional processes might insulate decision-makers from the consequences of their decisions – Diamond resorts to the simplistic notion of physical or social isolation. He says:

A society contains a built-in blueprint for failure if the elite insulates itself from the consequences of its actions. That’s why Maya kings, Norse Greenlanders and Easter Island chiefs made choices that eventually undermined their societies. They themselves did not begin to feel deprived until they had irreversibly destroyed their landscape.

In short, for Diamond, externalities exist principally when kings and sultans are isolated from their subjects; when rulers don’t share the current fates of their subjects. If only the sovereign – or his noble liegemen – knows of a problem and has sufficient incentive and good-will to solve it, things stand a good chance of turning out alright.

Is Diamond unaware that well-defined and divisible and exchangeable property rights tend to internalize on each decision-maker the larger value-consequences of his decisions on countless others – and, hence, prompt each decision-maker to act in ways that benefit not only himself today and tomorrow, but others as well? Does he not know that in the absence of such property rights, individuals can and do act in ways that are individually rational but harmful to many others?

Why the puerile "oh-my!-unless-our-leaders-know-of-potential-problems-and-act-to-save-us-by-giving-us-specific-instructions-on-how-to-behave,-we’re-doomed!" motif?

Diamond’s analysis is adolescent.