Our paper prepared for the APSA 2023 Annual Meeting

Abstract. Members of parliament who change their parliamentary party group (PPG) affiliation can be motivated by a variety of factors but the desire to improve their electoral prospects is often argued to be the among the most important. But does switching PPG affiliation improve or damage the electoral performance of those involved? We study the changes in electoral performance of Polish MPs involved in parliamentary party instability since mid-1990s using an original dataset on all instances of switching compiled by the INSTAPARTY (Party Instability in Parliaments) project. In addition to analyzing whether the MPs run for the parliament again in the following election, we zoom in on their electoral performance in terms of personal preference votes. We consider the electoral dividends of different types of switching and find that the effect of switching on personal electoral performance depends on the type of switching MPs were involved in.