Useless Approvals. The Italian Bicameralism and its Decisional Capacity

The literature on bicameralism has mainly taken into account the relative powers of the two legislative branches. Less attention has been paid to the congruence of their political preferences. Ceteris paribus, the impact of bicameralism on the policymaking process will be greater the more the political preferences of the second chamber differ from those of the first chamber (Tsebelis & Money 1997; Heller 2007). However, on one side, the political preferences represented in each chamber stem from various sources and it is not clear which one from time to time prevails; on the other side, the impact on policymaking is a multifaceted phenomenon, very hard to capture, both as a whole and in its individual components. Moreover, in many national contexts it is difficult to discern between the explanatory contribution of the discrepancy in the political preferences and the weight of different prerogatives in the law making process. In this perspective, Italy offers an ideal (and almost unique) setting to assess the role of the political preferences in the two houses. The two houses of the Italian parliament hold exactly the same prerogatives with respect to lawmaking and their relation with the government. In this paper, we try to address the consequences of their dissimilarity in terms of political preferences on the decision capacity of the Italian parliament for a relatively long period (1983-2013). Our dependent variable is the fate of a bill already approved in a chamber. When such a bill is not definitively approved as law, this can be considered as a failure in the decision capacity of the parliament. The discrepancy between the two chambers is calculated by considering a set of alternative measures: the position of the median party in the Chamber and the Senate along the main policy dimensions, the percentage of seats of all parliamentary parties in each chamber, the percentage of support enjoyed by the cabinet at the time of the investiture vote in each house, the percentage of seats controlled by government parties in each chamber, the weight of personal vote according to the different electoral systems and the difference in terms of professional backgrounds between deputies and senators. The analysis is conducted also by controlling for different policy areas. Preliminary results show that decision capacity has been slowly decreased for the last 20 years and that political discrepancy measured with “governmental-level” (versus “parliamentary-level”) variables has acquired stronger explanatory power during the most recent legislatures.