Arthur Okun - teacher at Yale in the 1950s, member and later Chairman of the President's Council of Economic Advisors in the 1960s, and Fellow of the Brookings Institution throughout the 1970s - was one of the three or four most important macroeconomists of the past twenty years. He was perhaps unique in having the respect and admiration of both academic economists and practical politicians. Okun was an effective mediator between the realms of economic...