Modeling revolutions in networked societies: learning from the Tunisian spring
Economic competition and deregulation have led to a polarization of societies between a small, increasingly powerful elite and a majority of socially excluded individuals, marginalized and unconnected to political representations. This is the breeding ground for protest movements, relayed by local ties and amplified by social networks. Based on the characteristics revealed by socio-economic research into the Arab revolutions of the 2010s, this article proposes a formalization inspired by the theory of complex systems. We discuss the conditions under which an initial localized event - for example, the suicide of a street vendor condemned to ruin in a small Tunisian town - can trigger an explosion of the number of opponents to the regime, typical of a revolutionary episode. We consider a network model of agents and oppressors where pair interactions are controlled by a fear parameter, or the inclination of the individuals to rebel despite of repression. The model exhibits a phase transition at a critical threshold above which the quiescent state becomes unstable. Furthermore, the ability of individuals to forge triadic relationships accelerates the process of joining a rising rebellion, making the transition more abrupt, in the form of a brutal discontinuity that can be described as revolutionary. The imposition of a counter-revolution by the hardening of repression can be explained by the hysteresis property displayed by the model: when mobilization has extended the initial network and made it partially permanent, repression by the authorities must be tightened to higher levels than before to regain control.