Rheinisch-Westfalisches Institut
für Wirtschaftsforschung
Board of Directors:
Prof. Dr. Christoph M. Schmidt, Ph.D. (President),
Prof. Dr. Thomas K. Bauer
Prof. Dr. Wim Kosters
Governing Board:
Dr. Eberhard Heinke (Chairman);
Dr. Dietmar Kuhnt, Dr. Henning Osthues-Albrecht, Reinhold Schulte
(Vice Chairmen);
Prof. Dr.-Ing. Dieter Ameling, Manfred Breuer, Christoph Danzer-Vanotti,
Dr. Hans Georg Fabritius, Prof. Dr. Harald B. Giesel, Karl-Heinz Herlitschke,
Dr. Thomas Koster, Tillmann Neinhaus, Dr. Gerd Willamowski
Advisory Board:
Prof. David Card, Ph.D., Prof. Dr. Clemens Fuest, Prof. Dr. Walter Kramer,
Prof. Dr. Michael Lechner, Prof. Dr. Till Requate, Prof. Nina Smith, Ph.D.,
Prof. Dr. Harald Uhlig, Prof. Dr. Josef Zweimüller
Honorary Members of RWI Essen
Heinrich Frommknecht, Prof. Dr. Paul Klemmer t
RWI : Discussion Papers
No. 41
Published by Rheinisch-Westfalisches Institut für Wirtschaftsforschung,
Hohenzollernstrasse 1/3, D-45128 Essen, Phone +49 (0) 201/81 49-0
All rights reserved. Essen, Germany, 2006
Editor: Prof. Dr. Christoph M. Schmidt, Ph.D.
ISSN 1612-3565 - ISBN 3-936454-65-5
The working papers published in the Series constitute work in progress
circulated to stimulate discussion and critical comments. Views expressed
represent exclusively the authors’ own opinions and do not necessarily
reflect those of the RWI Essen.