Polls that Mattered : Effects of Media Polls on Voters’ Coalition Expectations and Party Preferences in the 2005 German Parliamentary Election

While much speculated on, the effects of media polls on citizens' political perceptions and preferences have remained notoriously elusive in empirical research, in particular in field research using representative surveys. Applying a unique data base - a two-wave pre- and post-election panel survey of German voters whose first wave was designed as a rolling cross-section survey supplemented on a day-by-day basis with published data from media polls - this article demonstrates that polls mattered in the 2005 German parliamentary election in various ways. Combining aggregate-level time-series analyses with individual-level regression analyses, the study shows that expectations concerning the coalition seen as the most likely outcome of the election were strongly influenced by combined party shares reported by polling news. In particular, this pertained to voters who closely followed the polls. Our findings also indicate that at least for some parties polls even had an impact on voting behavior itself. Vote choices for the SPD and voting intentions for the Leftist Party were positively influenced by polling reports that suggested an improved standing of these parties. At least for the Social Democrats this again especially concerned voters who paid close attention to that kind of media content