 He was previously Research Economist at the Board of Governors of the Federal Reserve System in Washington, D.C.; Stuart Centennial Professor of Economics at the University of Texas at Austin; and Professor of Economics at Washington University in St. Louis.Prior to becoming an economist, he worked from 1963 to 1969, as an engineer at Rocketdyne division of the Rockwell International Corporation on development of the F-1 and J-2 rocket engines during Apollo program.His research is in macroeconomics and econometrics.