%S TSE Working Paper %A Lukas Buchheim %A Robert Ulbricht %T Dynamics of Political Systems %X We develop a quantitative theory of repeated political transitions driven by revolts and reforms. In the model, the beliefs of disenfranchised citizens play a key role in determining revolutionary pressure, which in interaction with preemptive reforms determines regime dynamics. We estimate the model structurally, targeting key moments of the data. The estimated model generates a process of political transitions that looks remarkably close to the data, replicating the empirical shape of transition hazards, the frequency of revolts relative to reforms, the distribution of newly established regime types after revolts and reforms, and the unconditional distribution over regime types. Using the estimated model, we also explore circumstances of successful democratization, finding that the sentiment of political outsiders is key for creating a window of opportunity, whereas the scope of the initial democratic reform is key for the survival of young democracies. %K Democratic reforms %K regime dynamics %K revolts %K structural estimation %K transition hazards %B TSE Working Paper %V 14-464 %D 2014 %C Toulouse %I TSE Working Paper %L publications15818