Interactions among simultaneous elections

In this study, we examine the interactions among elections by considering two parties competing in simultaneous elections, where each party fields candidates in every election. We model these interactions through voters' utility functions, influenced not just by the policies proposed in a specific election but also by those in concurrent elections. The benchmark result indicates that all candidates adopt positions more polarized than those predicted by the Calvert-Wittman model. This shift occurs because candidates leverage the policy stance of their counterparts in co-partisan elections to pursue policies more aligned with their preferences. In multidistrict elections, candidates from areas with strong ideological leanings deviate further from the median voter's stance at the national level. Moreover, this interaction effect may select candidates with more extreme ideology into the local elections.