The prime minister's chief of staff: Comparing profiles and trends in Westminster democracies, 1990–2021

Chiefs of Staff to heads of government hold a prominent position at the apex of the political executive. However, our knowledge of the personal and professional backgrounds of these unelected actors is surprisingly patchy. Not only is this an empirical gap, but it is also problematic as interactions between actors within political executives shape political decisions and ministerial operations. For this study, we present the most systematic dataset mapping the profiles of 56 chiefs of staff to prime ministers in four Westminster family countries from 1990 to 2021: Australia, Britain, Canada, and New Zealand. Their profiles are examined in relation to four concepts: (1) descriptive representation; (2) career de-separation; (3) institutional (in)stability; and (4) the revolving door. The demographic results illustrate how prime ministers' offices attract individuals with certain characteristics more than others. In order to bolster these results, more research on the chief of staff role is needed to demonstrate how prime ministers exert power and use these staff to strengthen their capacity to govern.