We investigate the dynamics of political systems in a framework where transitions are driven by reforms and revolts, and where political systems are a priori unconstrained, ranging continuously from single-man dictatorships to full-scale democracies. The dynamics are governed by the likelihood of transitions and their outcome, which are both determined endogenously. We find that reforms and revolts result in extreme political systems - reforms by enfranchising the majority of the population leading to democracies, and revolts by installing autocracies. Reinforcing this polarization, extreme political systems are persistent across time: Democracies are intrinsically stable, leading to long episodes without political change. Autocracies, in contrast, are subject to frequent regime changes. Nevertheless they are persistent, since ensuing revolts lead to autocracies comparable to their predecessors. Taken together, our results suggest that the long-run distribution of political systems is bimodal with mass concentrated on the extremes. The dynamics are consistent with cross-country data.
Endogenous dynamics of political systems invariant distribution persistence of regime types polarization transition paths unrestricted polity space