is the Stanley M. Zimmerman Professor of Economics and Finance. He has held positions at the University of Chicago, the University of Pennsylvania, the University of Minnesota and the Federal Reserve Bank of Minneapolis before moving to UCLA in 2000. He has published papers in the American Economic Review, Econometrica, the Journal of Political Economy and the Quarterly Journal of Economics. He is has been awarded nine NSF grants and has been an Associate Editor of the American Economic Review, Review of Economic Studies and Quarterly Journal of Economics. His research spans a variety of topics in macroeconomics, including the sustainability of international debt, the design of monetary policy and the measurement of the firm solvency.