How does turnover affect turnout? Government alternation and voter participation in parliamentary democracies

A crucial difference between political systems is the nature of government alternation: that is, whether when a government changes, all parties now in government were previously in opposition ('wholesale alternation') or whether just some parties were ('partial alternation') (Mair 1997). Bergman and Strom (2011) suggest that wholesale alternation gives voters a clear choice between alternative governments and allows them to hold the government accountable, while partial alternation is associated with one (centre) party becoming a (near-) permanent government party who can govern with either the parties to its right or to its left. However, this relationship has not been tested. We propose to examine the effect of partial and wholesale alternation on turnout in a large-N cross-country study, showing that there is an interaction effect between disproportionality and wholesale turn-out. Wholesale decreases turn-out but only when it when disproportionality is high.