Party competition and electoral reforms: why do governments initiate a reform?

Most accounts of electoral reforms focus on successfully implemented reforms to explain how electoral context shapes the incentives of political parties, paying scant attention to the cases where governments fail to implement their preferred system. This article takes a step back in the electoral reform process and examines when and why governing parties initiate electoral reforms. In doing so, it focuses on how the electoral context can affect the electoral bases of the incumbents and their main competitor. This novel account expects that governments initiate electoral reforms depending on whether small or new parties draw votes from their own vote base or from that of their main competitor. Using an original dataset of electoral reform attempts from 32 parliamentary democracies between 1945 and 2015, this article shows that ruling parties are more likely to initiate a restrictive reform when small parties draw votes from their electoral base, but a permissive one when small parties draw more votes from their main competitor.