Businesses are usually very keen to participate in the governance of their markets (Lazega and Mounier, 2002, 2003; Falconi et al., 2005). In this chapter, we combine a sociological perspective on joint governance of markets with an economic perspective, such as that of Dixit (2009) that deals with issues of social optimality of private or public governance and enforcement institutions. Institutional and neo-institutional economic theory often separate official governance institutions from private self-governance (Greif, 1996; Ellickson, 1991; Milgrom et al., 1990; Williamson, 1985). At the inter-organizational level, at least two different sociological traditions also deal with the issue of self and exogenous governance of markets, comparing the formal and often exogenous aspects with informal and endogenous ones (...).