1. Lawrence J. Christiano is the Alfred W. Chase Professor of Economics, Northwestern University, Evanston, Illinois.
2. Martin S. Eichenbaum is the Charles Moskos Professor of Economics, Northwestern University, Evanston, Illinois.
3. Mathias Trabandt is Professor of Macroeconomics at the School of Business and Economics, Freie Universität Berlin, Berlin, Germany and Research Fellow at the Halle Institute for Economic Research, Halle, Germany.