Does Policy Stability Increase the Constitutional Court's Independence? The Case of Italy During the First Republic (1956--1992)

In this paper, we consider the sentences of constitutional illegitimacy by the Italian Constitutional Court in the First Republic (1956--1992) as a measure of its independence from politicians. We focus on the Court's incidental review and test whether the Court's independence increases when there is more policy stability, namely when politicians are less able to change the policy status quo by legislation. We follow Tsebelis (2002) in assuming that legislative policy change is less likely when either the number and/or ideological distance of veto players increases. As a proxy for the size of the veto players' Pareto set, we use either the number of parties in government, or the number of parties forming a constitutional majority in Parliament, or the number of effective parties in Parliament, or measures of ideological distance based on Laver and Hunt (1992). By controlling for the Court's degree of internal cohesion, cointegration analysis shows that there is a stable and positive long-run relationship between the Court's independence and proxy measures of the degree of policy stability.