Legislators' behaviour and electoral rules: evidence from an Italian reform

We explore how electoral rules and cultural traits (namely, the degree of civicness) interact in shaping elected officials' behaviour. We use a dataset that includes the expenditure proposals sponsored by members of the Italian Senate from 1993 to 2012 (as well as other individual and district characteristics) and exploit the 2005 electoral reform that transformed a mainly majoritarian system into a proportional one. As a first step, we can confirm previous empirical findings: legislators elected in first-past-the-post districts show a higher propensity to sponsor locally oriented bills and to put effort into legislative activity than those elected with a closed-list proportional system. More importantly, however, we find that the effects of the change in the electoral rules are muted in areas with a high degree of civicness. We also propose a simple probabilistic voting model with altruistic preferences that is able to rationalize this finding.