Abstract
This article aims to explain longitudinal and cross-sectional variation in regional government composition – oversized majorities and incongruence between regional and national governments (cross-cutting) – and regional government alternation. The analysis focuses on the explanatory value of a wide range of regional-level institutional variables, such as majoritarian vs. proportional voting systems and established practices of consociationalism. In addition, it provides a tentative exploration of the impact of regional (i.e. non-state-wide) parties on government composition and alternation. The findings show that most institutional variables have the expected impact, e.g., majoritarian voting systems increase government alternation and consensual practices decrease both cross-cutting and alternation. The analysis also suggests that regional parties impact on government composition and alternation in two ways. Strong regional parties increase cross-cutting and, once in office, they tend to reduce alternation. Smaller regional parties out of office tend to increase alternation and to decrease oversized government as their seat shares grow.