Keywords: Parliamentary governments; Decision-making potential; Multidimensional index
This paper aims at answering the following questions: which dimensions best describe governments' decision-making potential in parliamentary democracies? How Italy (1979-2008), Germany (1976-2009), Great Britain (1979-2010) and Spain (1982-2008) can be categorized in terms of such dimensions? I try to achieve these aims by proposing a complex, multidimensional index combining the most important sources of governments' decision-making potential, namely: the ideological cohesion of the executive (the most important feature); the «colour» of the government compared with the previous one (alternation in office); the number of partisan veto-players; the institutional context i.e. the relationship between government and parliament; the size of parliamentary majority (the least important feature). This index fits quite well with qualitative literature on comparative governmental systems, and seems a reliable tool that scholars could use when studying the decision-making potential of parliamentary governments.