The Dynamics of Revolutions

Abstract. We study the dynamics of revolutions and mass protests and address a number of fundamental, but currently unanswered, questions about what triggers revolutions and who initiates them. Existing theories invariably predict that revolutions will be initiated by the most extreme opposition to the regime, like in the Iranian Islamic Revolution, but why are revolutions sometimes initiated by moderate opponents of the regime, like in the Egyptian Arab Spring and in many of the Anti-Communist Revolutions in Eastern Europe (including in the USSR)? And how can the implementation of popular policies trigger a revolution, as with Perestroika in the USSR? To address these and several related questions we present a theoretical framework in which society consists of citizens of different ideological or religious factions and of a regime that punishes dissent against it. We show that moderate opponents of the regime are likely to initiate a revolution whenever (1) citizens find it costly to deviate even slightly from their political ideology or religious conviction and (2) the regime’s policy of dissent-sanctioning distinguishes sufficiently between large and small dissent. In such a case, the regime will be effective in silencing its extreme opponents but will risk a rebellion by moderate factions of society. Furthermore, in this case implementation of popular policies by the regime may backfire and ignite a revolution. If these conditions are not satisfied, however, then the revolution, if it breaks, will be initiated by extremists. More generally, our model predicts which policies may trigger a revolution, which faction will start it and how dissent will evolve over time. The results are illustrated by several historic revolutions.