A Method to Separate Incumbency and Campaign Effects with Redistricting

• In Event: Elections and Campaign Spending in Legislative Politics

Abstract

We investigate name recognition of candidates to Coahuila's state assembly in the 2017 election---the first Mexican state since 1930 allowing incumbents on the ballot. Name recognition has been associated with representatives' efforts to preserve or enhance their reelectability. We propose a general method relying on redistricting to parse out incumbency effects from more standard campaign effects in name recognition. A pre-election survey provides evidence of systematic differentials (higher name recognition for incumbents than challengers and open seats; higher in precincts unchanged by redistricting than those that were removed/added; etc.) Just three incumbents were on the ballot, but the patterns uncovered conform to personal vote hypotheses. The method can be extended to other systems where redistricting preceded legislative elections.

Authors

• Eric Magar, Instituto Tecnologico Autonomo de Mexico

• Alejandro Moreno, Instituto Tecnologico Autonomo de Mexico