The Parliamentary Selectoral Power Index: Connecting the Investiture, Confidence, Non-Confidence and Dissolution Rules of the Confidence Relationship in Parliamentary Democracies

The confidence connection between parliament and government is at the heart of parliamentary democracies (Sartori, 1997; Lijphart, 2012). Executives are formed out of parliament through investiture votes and are held responsible to the people’s representatives via confidence and non-confidence votes – cabinets can only remain in office so long as they hold the confidence of parliament. Additionally, confidence is indirectly tested by dissolution rules as an early dissolution is either an outcome of a failure to gain or maintain confidence or a government with confidence choosing to go to the polls early. Despite the centrality of these four delegation and accountability mechanisms to the confidence connection, the literature tends to investigate each one individually rather than examine them together (for example, see Rasch et al., 2015; Sieberer, 2015; Huber, 1996, Williams, 2011; Strom et al., 2003; Heard 2007; Norton, 2016; Goplerud and Schleiter, 2016; Lento and Hazan, 2022). To that end, my dissertation project groups all four mechanisms with other relevant parliamentary and constitutional rules and conceptualizes them as the set of rules for the ‘confidence relationship.’ The confidence relationship structures executive-legislative relations on confidence matters over the parliamentary term. This paper builds upon the concept of the confidence relationship to develop the Parliamentary Selectoral Power Index (PSPI), which catalogues the rules of the confidence relationship and whether the rules promote or restrict parliament’s selectoral power on confidence matters relative to the executive. That is, whether parliament’s ability to hold the government to account is promoted or constricted and whether it can control its own fate. Using a sample of 28 established European and Westminster parliamentary democracies, this paper demonstrates the PSPI’s utility for understanding executive-legislative relations and how the delegation and accountability mechanisms of the confidence connection relate throughout the parliamentary term. The evidence shows that a) the sampled cases have adopted complex substitutability patterns between the four mechanisms, b) how, despite the variety of rules, most cases have a similar balance of parliamentary selectoral power between the executive and the legislature, and c) that there is a constructive turn in confidence relationships across the sample.