When should we ever expect to see durable moves toward greater wage bargaining coordination? Moving to sustained coordinated wage bargaining presupposes that unions and employers can both be convinced that wage bargaining is in fact a game in which both actors prefer coordination. This can only happen when these social actors come to accept as true an idea of the economy in which their coordination through wage bargaining institutions will give them better outcomes than would bargaining through decentralized institutions. This paper argues that the process of developing common knowledge changes institutional preferences among employers. It was the development of common knowledge that changed employer preferences about the attractiveness of institutions for wage coordination in Ireland in Italy. In both cases, the development of common expectations required the emergence and joint ratification of a common set of references, in what I call common knowledge events. These events led organized employers to change their previous position about acceptable institutions of wage bargaining. This change made possible the institutionalization of coordinated wage bargaining in both countries. As demonstrated through counterfactual analysis of the Australian case, the emergence and ratification of such a common view is the necessary condition for the emergence and survival of coordinated wage bargaining institutions.