Incumbency Effects in the German Mixed-Electoral System

Research question/goal: 

The literature on incumbency effects finds vote premiums for incumbent candidates in various institutional contexts. It has been shown that incumbency effects vary over electoral systems, with larger effects in single-member districts than in closed-list systems. In mixed-member electoral systems, however, incumbency can mean different things: having won the local district race in the first-past-the-post (FPTP) tier or having entered parliament via the party list in the proportional representation (PR) tier. Notably, in the German compensatory those two categories are not disjunct. What is the electoral benefit of each type of incumbency in the German mixed-member system? Are the effects only relevant to the respective tier, or do they spill over to the other tier? And how do these effects combine when PR incumbents simultaneously run in local district races, and vice versa? The project investigates those questions by analysing German federal elections from 1953 to the present.

Current stage: 

During 2019, the project’s data base was updated to include information on the recent 2017 federal election. First analyses on the spillover effects of different forms of incumbency on the party list vote in the proportional tier were conducted, focusing on how the incumbency bonus affects the party system and its tendency towards fragmentation. The results were presented at the APSA conference in August. The manuscript is currently being prepared for submission.

Fact sheet

2018 to 2022
in preparation
Data Sources: 
Information on candidates for Bundestag elections from official sources
Geographic Space: