N. Gregory Mankiw is the Robert M. Beren Professor of Economics at Harvard University. He is an active participant in academic and policy debates. His textbooks, Macroeconomics and Principles of Economics, have sold over 2 million copies and been translated into more than 20 languages. Mankiw has also been a research associate at the National Bureau of Economic Research and an adviser to the Congressional Budget Office and the Federal Reserve Banks of Boston and New York. From 2003 to 2005, he was chairman of the President's Council of Economic Advisers.