Paul Collier’s well-received book, “The Bottom Billion“, advocated military intervention alongside economic aid to improve security and economic growth in some of the world’s poorest countries. Iraq notwithstanding, the idea has caught on in official development circles–rhetorically, at any rate. In this review essay, Bill Easterly is unimpressed. By the time his tanks have rolled through, not much of Collier’s thesis is left standing. Bill’s article is recommended reading not just as an attack on Collier but as a warning about the social-science method as applied to development more generally.
In fairness to Collier, it is very difficult to demonstrate causal effects with the kind of data we have available to us on civil wars and failing states. As Collier writes, “our model cannot be used for prediction.” In the research papers on which his book is based, Collier does give abundant caveats that show he understands the limits of correlations for inferring that actions cause outcomes. But the caveats are not as apparent in the book, and Collier does not explain to the reader just why he recommends precise actions so confidently on the basis of mere correlations.
Of course, governments take many actions even when social scientists are unable to establish that such actions will cause certain desirable outcomes. Presumably they use some kind of political judgment that is not based on statistical analysis. What is unusual about Collier’s book is that he seems to offer statistical analysis as a replacement for political judgment, or perhaps unintentionally gives scholarly cover for actions that governments want to take anyway. The press shows a certain reverence for social science work with statistics that can make this cover quite effective. The paradox is that many social scientists familiar with this kind of analysis do not share the press’s reverence.
