The Size and Sources of Municipal Incumbency Advantage in Canada

This article uses a new dataset of nearly 2,000 municipal elections from 1874 to 2018 to estimate the size of municipal incumbency advantage in Canada for the first time. Incumbency increases the probability that a candidate will win the next election by more than 30 percentage points and accounts for well over half of overall incumbent success. Incumbency advantage varies modestly by institutional context but varies substantially over time, with a distinct decrease during a period of partisan elections in the mid-twentieth century. These findings represent one of the first estimates of municipal incumbency advantage in an advanced democracy outside the United States and provide a new approach to estimating and comparing incumbency advantage in multi-member and single-member districts. The findings suggest important similarities between Canadian and American municipal elections, demonstrate that incumbency advantage has varied significantly at the municipal level over time, and illustrate the value of historical election data for scholars of urban electoral politics.