Illegal markets boundaries and interfaces between legality and illegality

In sociology generally, the infringement of legal norms is not treated as a special kind of norm violation, the sociology of law being an obvious exception. The study of illegal markets therefore faces the challenge of distinguishing illegality from legality, and relating 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: there is both legitimate illegal action and illegitimate legal action. Illegal markets are a special kind of illegal social system, constituted by market transactions. 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, actions that are illegal but perceived as legitimate or the other way around, and a gray zone of actions that are neither clearly legal nor illegal, and neither clearly legitimate nor illegitimate. Interfaces facilitate interaction between legal and illegal action systems, but they are also sources of tension and can lead to institutional change.