This paper explores the global incumbency advantage. We first show that existing subnational estimates of the incumbency advantage correlate positively with GDP per capita and democratic quality, and negatively with corruption across countries. Building on this meta-analysis, we then consider all presidential and parliamentary elections held since 1945 to estimate how a national electoral victory affects the probability that winning parties and candidates retain power beyond the term for which they were elected. On average, national election winners benefit from an incumbency advantage, but this effect is short-lived and differs markedly across contexts: it is large in Africa, North America, and Western Europe, but muted or even reversed in other regions. We explore how standard incumbency effects and electoral manipulation contribute to these results. In established democracies, the national incumbency advantage reflects gains in the subsequent electoral performance of election winners. In less democratic regimes, it mainly stems from manipulation of the fairness and the timing of elections. Overall, this advantage is largest in both the most and the least democratic countries, due to radically different types of equilibria.<br><br>Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at <a href="http://www.nber.org/papers/&#119;34968" TARGET="_blank">www.nber.org</a>.<br>