Who matters in dynamic coordination problems

This paper studies a dynamic coordination model with timing frictions and heterogeneity in several dimensions. Each agent might a ect and be a ected by others in di erent ways, and the frequency of their decisions might di er. There is a unique equilibrium in the model. At times, the economy might be stuck in an ine cient low-output equilibrium, and subsidies can improve welfare. The optimal subsidy does not depend on each type's timing frictions: at each point in time, the planner should simply compensate each agent for its externality on others at that particular moment.