The defining feature of parliamentarism, in contrast to presidentialism, is that the governing executive ‘comes from’ and ‘remains responsible to’ the legislature. So much so, a core role and function of modern parliaments under parliamentarism is said to be the making and breaking of governments. Despite this, and a significant literature on coalition formation, we know surprisingly little about the role of parliaments in how governments are selected. Some require a formal vote to select the (head of) government, others vote to confirm the choice made by another player (such as the head of state or formateur), and yet others never positively endorse a government. We present a new dataset of government investiture rules which illustrates significant variation in institutional design, even among otherwise similar political systems. We introduce and test a number of explanations to account for this variation, including the effect of geographical clustering, the timing of constitutional adoption and adaptation, experiences of un-governability, the levels of party fragmentation and the complexity of coalition building, and whether investiture rules correlate with other instruments of executive privilege in the legislative arena.
