Do voters reward or punish incumbents for retrospective performance similarly in different democratic regimes? Despite debates on the merits of different regimes, little research has investigated the implications of constitutional design on voters' ability to hold politicians to account. This article shows that regime type determines the way and extent to which elections enable voters to reward or sanction incumbents. These regime effects are separate from and conceptually prior to factors previously identified in the literature on comparative economic voting. Analysis of elections from seventy-five countries reveals that, all else equal, voters have greater potential to hold incumbents to accounts under the separation of powers than under parliamentarism. Moreover, variables particular to separation of powers systems - the electoral cycle in pure presidential systems and instances of cohabitation in semi-presidential systems - affect the relative impact of the attribution of responsibility. The results contribute to ongoing debates about the relative advantages of different constitutional formats for democratic performance.