Opportunism and MPs’ chances of re-election. An analysis of political transformism in the italian parliament

We identify as political transformists the Italian members of parliament (MPs) who cross the aisle and vote for legislation opposed by their own political group—i.e., MPs who transform from the political opposition to the ruling parties (or from government supporters) into a force supporting the government (or opposition)—thus representing sources of party and governmental instability. Transformism, which characterized 471 MPs over the period considered, does not coincide with the broader phenomena of party switching already studied in political science. Once we disentangle the distinct behaviors, we study whether transformism helps extend the tenures of all 7128 MPs observed from 1946 to 2013. To the best of our knowledge, ours is the first work to consider the role of transformism in the survival of politicians. Our results suggest that transforming MPs suffer marked reductions in their survival probabilities, especially when compared with their fellow parliamentarians. However, transformist MPs, immediately after coming out as such, are more likely to survive than MPs remaining reliably loyal to their parties. That is, over time, transformists are punished by the electorate, but newly transformed politicians enjoy short-term comparative electoral advantages, thus shedding light on the relevance of a long-standing Italian political phenomenon.