In this paper we analyse the effect of constitutional structures over policy outcomes. In particular, we exploit the heterogeneity in parliamentary systems deriving from the presence and the use of the confidence vote to investigate whether stable and unstable parliamentary systems behave differently in terms of the policies they implement. This finer partition of parliamentary systems allows us to identify effects that are more robust than the ones previously discussed in the literature. We show that the difference between presidential and parliamentary systems documented in previous works is driven by a difference between presidential and stable parliamentary systems. We suggest that possible transmission channels are legislative cohesion and (the absence of) selection.

在本文中，我们分析了宪法结构对政策结果的影响。特别是，我们利用议会制的存在和使用信任投票产生的异质性，来研究稳定和不稳定的议会制在执行政策方面是否表现不同。议会制度的这种更精细的划分使我们能够确定比先前文献中讨论的效果更强大的效果。我们表明，先前著作中记载的总统制与议会制之间的差异是由总统制与稳定议会制之间的差异驱动的。我们认为，可能的传播渠道是立法凝聚力和（没有）选择。