Local Councils Boost National Vote Share, Especially for Opposition Parties

Why This Question Matters

Emanuel Coman investigates whether the diffusion of power to local authorities across Europe has made local politics more consequential for national elections. The central claim is a cross-level incumbency effect: parties that control a majority of seats on local councils enjoy an electoral advantage when voters go to the polls nationally. This question speaks to debates about decentralization, party organization, and how local political strength translates into national influence.

What the Study Uses

Coman compiles an original, cross-national dataset linking locality-level results from 62 national elections in 15 European countries with prior local election outcomes. That pairing lets the analysis compare national vote performance in areas where parties recently did well or poorly at the local level.

Causal Strategy and Methods

To address endogeneity—where local party strength and national vote choice might be jointly determined—the study uses a regression discontinuity design (RDD). The RDD focuses on councils where a party barely won versus barely lost a majority of seats, treating these close wins as quasi-random shocks to local incumbency. This approach isolates the local incumbency effect on subsequent national vote shares.

Key Findings

• The estimated local council incumbency advantage is roughly one percentage point in national elections for parties that control a local council majority.
• This advantage is concentrated among parties that are not in national government; governing parties do not receive the same local boost.
• The pattern is consistent across the pooled sample of 62 elections and 15 countries, suggesting a generalizable cross-level effect tied to local officeholding.

Implications for Parties and Devolution

The results indicate that devolution and stronger local institutions can make municipal victories electorally valuable beyond immediate policy control. For opposition and non-governing parties, winning local council majorities appears to produce measurable national returns, which matters for campaign strategy, party investment in local races, and theories of multi-level party competition.