This study was accepted as a doctoral thesis by the Department of E-
nomics of the Johann Wolfgang Goethe-University in Frankfurt/Main. It
was undertaken within the research project 'The E?ects of Job Creation
and Structural Adjustment Schemes on the Participating Individuals',
which was conducted by the Institute of Statistics and Econometrics
(Empirical E- nomic Research) in cooperation with the Institute for
Employment Research in Nuremberg. I have to thank numerous people. First
of all my thesis supervisor, Prof. Dr. Reinhard Hujer, for initiating
this thesis and providing me with a great scienti?c environment. I owe
the data I used to his persistent lobbying to promote and anchor
evaluation research in Germany. I am also very grateful to Prof. Dr.
Roland Eisen who did not hesitate to act as the second thesis
supervisor. Thanks also to Christian Brinkmann and his team at the
Institute for Employment Research (Institut fur ] Arbeitsmarkt- und
Berufsforschung) for valuable help with the datasets.
Ihavealsobene?tedfromcontinualdiscussionswithmycolleaguesStephan
L.(!)Thomsen, DubravkoRadic, PauloRodrigues, SandraVuleticandChris- pher
Zeiss. A warm thanks goes also to Birgit Kreiner and all our current and
former student research assistants.