Contagious populists: The impact of election information shocks on populist party preferences in Germany

This study analyzes the role of social contagion in populist party support. Although the emergence of the German right-wing populist AfD was accompanied by controversial debates about the social acceptability of its nationalist program, electoral support has followed a clear upward trend. We analyze the impact of information shocks with respect to aggregate-level support for the AfD on individual vote intentions. Unexpectedly high aggregate support for a populist party may indicate a higher social acceptance of its platform and reduce the social desirability bias in self-reported vote intentions. Consequently, the likelihood that an individual will reveal an AfD vote intention increases. We test this mechanism in an event-study approach, exploiting quasi-random variation in survey interviews conducted around the time of German state elections. We define election information shocks as deviations of actual AfD vote shares from pre-election polls and we link these shocks to an individual’s likelihood of reporting an AfD vote intention in subsequent survey interviews. Our results suggest that exposure to higher-than-expected AfD support significantly increases the probability of reporting an AfD vote intention by up to 2.7 percentage points. Testing alternative mechanisms, we find that this increase is in fact driven by reduced reputational concerns associated with expressing populist support.