Electoral Reform, Regional Cleavages, and Party System Stability in Bolivia

This research note considers the effects of electoral system reform in Bolivia. In 1995, Bolivia moved from a list-proportional to a mixed-member proportional electoral system. The intervening years saw growing regional polarization of politics and a collapse of the existing party system. Using statistical analysis of disaggregated electoral data (at department, municipality, and district level), this paper tests whether electoral system reforms may have contributed to the current political crisis. Research findings show that regional cleavages existed prior to electoral system reform, but suggest that reforms aggravated their effects. Such evidence gives reason to question the recent popularity of mixed-member proportionality.