Research shows that combining elections increases voter turnout. What has largely been neglected, however, is that combining can also shift the balance of power between parties. This paper aims to fill that research gap. It examines how synchronising European Elections with local and other elections affects electoral outcomes in Germany. Germany provides an ideal case for analysing the partisan effects of electoral concurrency: in some states European elections coincide with local contests, while in others they do not. This variation allows the use of panel data regression models to estimate the effects. The findings suggest that combining European and local elections particularly benefits parties with a Eurosceptic electorate, which struggle with voter mobilisation in standalone European elections. Meanwhile, parties whose voters are predominantly pro-European are losing vote shares as most of their supporters are taking part in the European elections anyway.
J. Baumert (Fri,) studied this question.