Partisan Identity Predicts Voting Better Than Ideology in Three European Democracies

Why This Question Matters

Scholars disagree about whether partisanship is primarily a strategic, performance-based attachment or a stable social identity that shapes emotions and motivated reasoning. Understanding which view is more accurate matters for interpreting voter behavior, campaign effects, and polarization—especially in multi-party European systems where party loyalties can be less straightforward than in two-party contexts.

What Alexa Bankert, Leonie Huddy, and Martin Rosema Did

The authors evaluate the nature of partisanship across three European democracies (the Netherlands, Sweden, and the U.K.) by comparing a multi-item partisan identity scale to conventional measures. They use national survey data from each country and estimate a latent variable model to assess the scale's measurement properties and predictive power.

How Partisanship Was Measured

• The central measure is an eight-item partisan identity scale designed to capture the strength and expressive quality of party attachment.
• This is contrasted with a standard single-item measure of party identification and with an ideological intensity measure based on left–right self-placement and agreement with the party on key issues.
• A latent variable approach probes how much information each measure provides and whether the scale works the same way across countries.

Key Findings

• The eight-item partisan identity scale offers more information about partisan intensity than the standard single-item measure.
• The scale shows the same measurement properties (i.e., measurement invariance) across the Netherlands, Sweden, and the U.K., supporting valid cross-national comparison.
• The identity scale predicts in-party voting and political participation better than the ideological intensity measure, lending empirical support to an expressive identity view of partisanship in these multi-party settings.

Implications for Research and Practice

The results suggest researchers studying voter behavior in multi-party democracies should favor richer, multi-item identity measures over single-question or purely ideological indicators when the goal is to capture the social-identity dimension of partisanship. That choice affects both measurement precision and the interpretation of how partisan attachments drive turnout and vote choice.