Twenty-five years ago, economics was in a crisis even if most economists weren’t aware of it. The discipline was slipping away from answering big questions, the sort people really cared about. As Noam Scheiber pointed out in a New Republic cover story in 2007, the conventional wisdom was that "the path to knowledge lay in solid answers to modest questions.”

But, at about the same time, Daron Acemoglu, James A. Robinson and Simon Johnson were tackling the biggest possible questions: Why do some countries succeed and others fail? One worked in an academic economics department, one in political science and the third in a business school, and the answers they came up with lay between all those disciplines. They weren’t "solid” answers, perhaps — you can poke holes in many of them, and many of us did. But their questions weren’t modest and that’s what counts.

When I was first introduced to the paper that became known by their initials — "AJR, 2001” — in a stuffy Cambridge seminar room 24 years ago, that ambition stood out. Why were countries that were rich in 1500 poor today, and vice versa? Their answer was, for better or worse, "institutions” — the constraints that are imposed on arbitrary power, the way interest groups share the exercise of power, the protection against expropriation, and so on. Some institutions were designed to be extractive, to maximize revenue for an elite or foreign minority while not serving the interests of the broader public; others were more inclusive and dynamic. According to the neo-institutionalist school that kicked off with AJR 2001, only the second kind worked.