Is the grass really greener? The rationale and reality of support party status: A New Zealand case study

The motives, behaviour, treatment and fate of parties which, rather than joining governments provide them with a working legislative majority, are not well studied. In the light of coalition theory, we explore these issues by way of observation research on New Zealand's Green Party since 1999 a support party to a minority centre-left government. We isolate three factors important in coming to this type of arrangement ideology, calculation and the institutional environment - all mediated by party system variation. The relative importance of each factor, however, is less significant than the links and trade-offs between and within them. We go on to show how non-institutionalized support arrangements are unlikely to be 'win-win' situations, leading to frustrations which themselves may become a factor in the decision to support or join after the next election.