We consider competitive markets for multiple commodities with endogenous formation of one- or two-person households. Within each two-person household, externalities from the partner’s commodity consumption and unpriced actions are allowed. Each individual has two types of traits: observable...

We develop a model that combines competitive exchange of private commodities across endogenously formed groups with public good provision and global collective decisions. There is a tension between local and global collective decisions. In particular, we show that group formation and collective...