The Effects of Proportional Seat Allocation Methods upon Legislative Fragmentation: Evidence from Russia

Abstract

This article examines the effects exerted by different seat allocation methods upon legislative fragmentation, conventionally operationalized as the effective number of parliamentary parties (ENPP), in proportional representation systems. A real-life data set of 191 sub-national elections held in Russia in 2001–13 is used to assess relatively restrictive methods, Imperiali and d'Hondt highest averages, against a more permissive method, Hare largest remainders. Statistical analysis demonstrates that if fragmentation in the electorate and the amount of wasted votes are properly controlled for, the effects of proportional seat allocation rules can be assessed with a high degree of precision. The Imperiali method reduces the ENPP by 0.34 in comparison with the Hare method, while the d'Hondt method makes it smaller by 0.12. Restrictive seat allocation rules suppress legislative fragmentation primarily because they lead to the over-representation of major parties.