Political Polarization and the Asymmetric Fragility of Political Regimes

Why do democratic and autocratic regimes fail under different political conditions? Using V-Dem data for 202 countries over 1900-2024, we construct regime spells and estimate duration models with lagged covariates. The apparent unconditional durability advantage of autocracy is largely driven by regimes already in place when observation begins in 1900. Among spells observed from entry, and in models controlling for observable characteristics and historical environment, autocratic spells exhibit higher exit hazards. Political polarization strongly predicts democratic termination but is weakly associated with greater autocratic persistence. It rises before democratic breakdown and declines before and after democratization, although the latter pattern lies outside the baseline model. Autocratic survival is associated non-monotonically with repression, while democratic regional environments are strongly associated with autocratic exit. A parsimonious framework explains the central asymmetry: polarization raises the costs of democratic policy competition, whereas concentrated authority creates vulnerabilities through extraction and coercive overreach.