The market of infidelity. The effect of party switching on lawmaking productivity: Evidence from Italy.

This paper explores the phenomenon of party switching in the Italian parliament, wherein elected politicians frequently shift allegiance from one party to another, often at the expense of voter representation. Analyzing data on parliamentarians spanning 2008 to 2013 and utilizing an instrumental variable approach, the study reaffirms existing literature highlighting the influence of historical institutions on cultural beliefs and norms. These enduring legacies, passed down across generations, significantly impact the establishment, framework, and operation of current institutions. The manuscript specifically reveals that politicians elected in regions historically linked to enduring feudal values from pre-unitary kingdoms are more prone to defection and changing political affiliations. This tendency to switch parties reflects specific social norms and institutional influences deeply rooted in established clientelist practices. Ultimately, the evidence presented underscores how parliamentarians’ defection diminishes legislative productivity, substituting particular interests for the nation’s welfare. In summary, these findings demonstrate the persistent impact of informal cultural values originating from centuries-old institutions, shaping incentives and behaviors in contemporary politics despite the absence of formal institutional changes.