1. Institute for Fiscal Studies, 7 Ridgmount St, WC1E 7AE, London (e-mail: )
2. European Bank for Reconstruction and Development (EBRD), One Exchange Square, EC2A 2JN, London, and Tilburg University (e-mail: )
3. EBRD and WZB. EBRD, Emmar Towers, 196 Zahran Street, 15th Floor, P.O. Box 852805, Amman 11185, Jordan (e-mail: )
4. Department of Economics, Yale University, Box 208264, New Haven, CT 06520 (e-mail: )