[1] Univ Oxford, Dept Econ, Manor Rd Bldg, Oxford OX1 3UQ, England
[2] Nederlandsche Bank, Econ, NL-1017 ZN Amsterdam, Netherlands
[3] Nederlandsche Bank, Dept Res, NL-1017 ZN Amsterdam, Netherlands
[4] Univ Milano Bicocca, Dept Econ, Piazza Ateneo Nuovo 1, I-20126 Milan, Italy
[5] Univ Pavia, Dept Econ & Management, Econ, Via San Felice 5, I-27100 Pavia, Italy