Institutional constraints on cabinet formation: Veto points and party system dynamics

Research on government formation in parliamentary democracies has presented contradicting evidence on the role of political veto institutions and parliamentary polarization on the formation of cabinet types. Institutional rules may either provide significant leeway for political parties or seriously constrain them when forming sustainable coalitions. In contrast to previous studies we argue that the effect of political institutions is conditional on the degree of polarization in parliament. We test our hypotheses using original data on 842 cabinet formations in 33 advanced democracies between 1945–2018. In line with previous research, we find that the institutional rules have a pronounced effect on the type of cabinet formed, but that institutional rules moderate the effect of party system polarization. Thus, our findings provide important new insights on cabinet formation which are particularly relevant for today's increasingly polarized parliaments.