This paper investigates the disincentive effects of the potential duration of unemployment insurance (UI) benefits. The disincentive effects are identified by exploiting changes in the UI system in Slovenia, which involved substantial reductions in the potential benefit duration and had characteristics of a "natural experiment". We find that the change had a positive effect on the exit rate out of unemployment -both to employment and to other destinations -at various durations of unemployment spells and for many categories of unemployed workers.Keywords: Unemployment Insurance, potential benefit duration, job finding rates JEL-codes: C41, H55, J64, J65 * Tilburg University, CentER, IZA, and CEPR; corresponding author: Department of Economics, Tilburg University, P.O. Box 90153, 5000 LE Tilburg, The Netherlands; email: vanours@uvt.nl † World Bank; email: Mvodopivec@worldbank.org ‡ The authors wish to thank The National Employment Office of Slovenia for providing the data used in the study. Jakob Tomse provided excellent assistance in setting up the data sets. Support form the World Bank research project "Incentive Effects of UI systems in Transition Countries" (RF-P087059-RESE-BBRSB) is gratefully acknowledged. The authors also thank participants at seminars in Canberra (RSSS), University of Melbourne, University of Sydney, Brussels (EU), Tilburg, the IZA prize ceremony (Berlin), Maastricht and Florence for their comments on a previous version of this paper, which has been revised substantially (Van Ours and Vodopivec, 2004). They also thank participants at a Paris I seminar (TEAM) for comments on a more recent version of the paper.