Duration of Party Control in Parliamentary and Presidential Governments A Study of 65 Democracies, 1950 to 1998

Most of the previous work on political stability uses cabinet duration or leadership duration to measure stability. This study, however, focuses on another area of stability, namely the party control of the executive branch. This approach not only allows us to compare political durability in presidential and parliamentary systems directly, but it also, we believe, better reflects policy changes that stem from government party composition. Our analysis of longitudinal data from 65 democracies reveals that presidential and parliamentary governments create different patterns of government survival. Ruling parties in parliamentary systems encounter a declining hazard rate over time, whereas those in presidentialism face an increasing hazard rate in their survival. We explain this difference by focusing on how parliamentary and presidential systems create different incentive structures for political parties.