Fragility and regime stability in a state–society dynamic model

This paper develops a continuous-time dynamic model in which state capacity and societal power evolve jointly as institutional stocks subject to investment incentives, contest effects, and baseline decay. The interaction between these forces generates multiple political regimes, including a despotic regime, a weak-state regime, and a balanced regime in which state and society co-develop. The model admits a corridor of regime stability whose thickness depends on contest intensity and structural parameters, and whose boundaries determine the basins of attraction of the competing regimes. Extending the system to a stochastic environment, the paper characterizes regime fragility by deriving corridor-exit probabilities, showing how volatility increases the likelihood of transitions toward despotism or state collapse. The analysis highlights how institutional balance can be sustained dynamically, yet remains inherently fragile in the presence of shocks.