The completion of this thesis gives me feelings of satisfaction and thankfulness. Satisfaction because its results appear to be worthwile and relevant, and thankfulness towards so many persons who contributed to the progress of the work. The project "Analysis of multilevel decisions" was granted by the common research pool of Tilburg University and Eindhoven University of Techno- logy (Samenwerkingsorgaan Brabantse Universiteiten). During the 4-year lead time, the Department of Econometrics of Tilburg University provided not only a single room but also a pleasant and inspiring environment, for which I am very grateful. The research itself, particularly the inevitable scientific struggles, was perfectly coached by my promotors, Prof. Dr. P.A. Verheyen and Prof. Dr. J.F. Benders. I cannot give even the slightest description of the unique way in which they managed to do this. In all criticism they succeeded to maintain a positive, and thus stimulating, working atmosphere. The work also benefited from the suggestions gi ven by Prof. Dr. Th.M.A. Bemelmans, Prof. Dr. J.P.C. Kleijnen, Prof. Dr. P.H.M. Ruys and Prof. Dr. A. Schrijver. Furthermore I am indebted to Dr. Adam Wofniak (Warsaw University of Technology), who made me participate in his multi- level experience and critically commented on an earlier draft of the thesis.