This article investigates hypotheses generated by the veto players' theory. The fundamental insight of this theory is that an increase in the number of veto players (for all practical purposes, in parliamentary systems the number of parties in government) and their ideological distance from one another will reduce the ability of both government and parliament to produce significant laws. In addition, the number of significant laws increases with the duration of a government and with an increase in the ideological difference between current and previous government. These propositions are tested with legislative data (both laws and government decrees) on working time and working conditions identified in two legislative sources: the NATLEX computerized database in Geneva (produced by the International Labour organization) and Blanpain'sInternational Encyclopedia for Labour Law and Industrial Relations.The data cover fifteen West European countries for the period 1981–91. The evidence corroborates the proposed hypotheses.