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 theory and analysis and the making and implementation of public policy. These thirty-one essays, whether they first appeared in the American Economic Review or in the New York Times Magazine, are all marked by a lucid and readable style of writing and by a willingness to grapple with real economic, social, and political problems. They are grouped under eight headings: Inflation: Causes and Cures; Implicit Contracts; Output, Employment, and Unemployment; Fiscal and Monetary Policy; Economic Performance, 1960-1980; Economic Forecasting; Economic Policy Formulation; and Equality and Efficiency.