The study of illegal markets needs to distinguish illegality from legality, and to relate both to legitimacy. There is no conceptual ambiguity about the distinction between legal and illegal if legality is formally defined. In practice, (formal) legality and (social) legitimacy can diverge: illegal markets are empirically related to organized crime, mafia, and even terrorist organizations, and they interact both with legal markets and the forces of state order. Where legal and illegal action systems are not separated by clear social boundaries, they are connected by what has come to be called “interfaces”: actors moving between a legal and an illegal world, and grey zones of actions that are neither clearly legal or illegal, nor clearly legitimate or illegitimate. Interfaces facilitate interaction between legal and illegal action systems, but they are also sources of tension and can lead to institutional change.
Complex-balanced equilibria of generalized mass-action systems: necessary conditions for linear stability
