Single-member district electoral systems and democratic transition

A considerable number of democratizing states have made the transition to competitive politics on the basis of single-member district electoral systems. This paper argues that such electoral systems often do not provide viable mechanisms for the consolidation of democracy. This is because the use of single-member districts works against the institutionalization of democratic politics in a newly competitive state. If the party system is geographically heterogeneous and/or poorly entrenched, a single-member law will encourage the multiplication of small, regionalized political support bases and the dominance of one large party. This aspect of electoral institutional design is therefore likely to be destabilizing, making it possible to predict that states which inherit or adopt single-member systems will either change their electoral systems or fail to democratize. This hypothesis is tested and largely confirmed on an exhaustive set of 78 cases from the 'third wave' of democratization.