Reduced Incentives, Reduced Party Unity: Evidence from Parliamentary Speeches

Abstract

This article examines how reductions in individual legislators' political incentives affect their relationship with their party in a party-centered environment. We develop a principal-agent framework to argue that the absence of re-election incentives and diminishing prospects of attaining higher legislative offices increase the likelihood of agency loss, manifested in weaker adherence to party positions in parliamentary speeches. We hypothesize that when MPs are unable to run for re-election and face increasingly limited career advancement opportunities over the course of the electoral period, the mechanisms party leaders rely on to foster party unity become less effective, making these MPs more likely to deviate from the average party positions. To test these expectations, we leverage the case of the Five Star Movement’s party-imposed term limits in Italy. We draw on an original dataset of speeches delivered in the Italian Chamber of Deputies between 2013 and 2022. The results support our hypotheses, showing that reduced individual political incentives are associated with systematic increases in intra-party deviation in parliamentary speech.