Robert E. Lucas, Jr., in full Robert Emerson Lucas, Jr., (born Sept. 15, 1937, Yakima, Wash., U.S.), American economist who won the 1995 Nobel Prize for Economics for developing and applying the theory of rational expectations, an econometric hypothesis. Lucas found that individuals will offset the intended results of national fiscal and monetary policy by making private economic decisions based on past experiences and anticipated results. His work, which gained prominence in the mid-1970s, questioned the conclusions of John Maynard Keynes in macroeconomics and the efficacy of government intervention in domestic...