Do (weak) upper houses matter for cabinet formation? A replication and correction

Abstract

Do upper houses matter for cabinet formation? If so, does it make a difference how powerful they are? The most sophisticated study to give clear answers to these questions is still that of Druckman, Martin and Thies (2005), which argues that upper houses influence cabinet formation, regardless of their formal powers. We dispute these answers theoretically and empirically. Since adjusting cabinet formation to second chamber composition is not necessary and can be costly, we should expect that if upper houses matter at all, their formal powers should matter too. Replication shows that the empirical results are driven exclusively by two countries with weak upper houses, one of which (Ireland) is miscoded. If this case is recoded there is no statistically or substantially significant effect of upper houses, regardless of their power. We conclude that the two questions cannot yet be answered: we need more research based on broader samples in order to assess whether upper houses matter for cabinet formation and whether their formal powers make a difference.