Collective consumption decisions taken by the members of a household may prove inefficient. The impact on market performance depends on whether household inefficiencies are caused by inefficient net trades with the market or by inefficient distribution of resources within households. Inefficient...

We present a variant of a general equilibrium model with group formation to study how changes of non-consumptive benefits from group formation impact on the well-being of group members. We identify a human relations paradox: Positive externalities increase, but none of the group members gains in...