Klein, Lawrence Robert, 1920–, American economist, b. Omaha, Nebr., Ph.D Massachusetts Institute of Technology, 1944. He was active in academia, government, and private research institutes throughout the world from the 1940s; he joined the faculty at the Univ. of Pennsylvania in 1958, becoming professor emeritus in 1991. Klein's 1947 book The Keynesian Revolution established him as one of the foremost scholars on Keynesian economics. His influential studies in econometrics brought him further recognition, particularly his book An Econometric Model of the United States, 1929–52 (1955, repr. 1966). The econmetric models he created became widely used by countries and organizations to make economic forecasts concerning gross national product, exports and imports, investment and consumption, and the possible affect of government policies on the economy. In 1980 he was awarded the Nobel Memorial Prize in Economic Sciences for his work on developing econometric models.