Resumen de Balancing Costs of Legislative Party Switching in the Danish Parliament 1953–2015

Marie Kaldahl Nielsen, Ann Møgeltoft Andersen, Helene Helboe Pedersen

• When elected politicians switch party, it disturbs the electoral connection to voters. Party switching is thus described as a betrayal of democratic representation (Heller and Mershon, 2009, Political Parties and Legislative Party Switching, p. 5). In this article, we argue that party switching results from intra-party conflicts in which individual legislators weigh costs of switching against costs of staying. These costs depend on the legislator’s position in the party as well as the party’s position in the legislature. To explain party switching, we propose two new explanations: personal votes and intra-party balance of power. The study is based on all Danish national legislators elected from 1953 to 2015 (N = 3850) and utilises a mixed methods design including news coverage of each switch to inform the interpretation of the statistical results. We conclude by suggesting that party switching can increase accountability rather than betray representation.