1. RWTH-Aachen University, Templergraben 64, Rm. 513, 52062 Aachen, Germany, National Bureau of Economic Research, IFO Institute, and CESifo.
2. Ifo Institute Business Cycle Analyses and Surveys, Poschingerstrasse 5, 81679 Munich, Germany.
3. University of Notre Dame, Department of Economics, 434 Flanner Hall, Notre Dame, IN 46556, National Bureau of Economic Research, and IFO Institute.