Local ethnic cleansing to genocide. Credit: Courtesy of Princeton University Press

Paul Krugman, the distinguished Princeton University economics professor and New York Times columnist, once explained the jejune motives for his choice of career. "In my early teens my secret fantasy was to become a psychohistorian," he wrote, referring to the central gimmick, "psycho­history," of Isaac Asimov's Foundation trilogy. Krugman continued, "Someday there will exist a unified social science of the kind that Asimov imagined, but for the time being economics is as close to psycho­history as you can get."

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