A non-cooperative model of network formation is developed. Agents form links with others based on the cost of the link and its assessed benefit. Link formation is one-sided, i.e., agents can initiate links with other agents without their consent, provided the agent forming the link makes the...

This monograph studies multi-member households or, more generally, socio-economic groups from a purely theoretical perspective and within a general equilibrium framework, in contrast to a sizeable empirical literature. The approach is based on the belief that households, their composition,...

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 study the allocation of commodities through a two-stage hierarchy of competitive markets. Groups or countries trade at global prices while individuals within a group trade at local prices. We identify the free trade and the autarky equilibrium as polar cases. We show that no other two-stage...

We propose a formal concept of the power of voice in the context of a simple model where individuals form groups and trade in competitive markets. Individuals use outside options in two different ways. Actual outside options reflect the possibility to exit or to join other existing groups....

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 study stable matchings on exogenously given or endogenously formed bipartite graphs that reflect constraints on matching. The effects of a change of the exogenously given graph (constraints) are investigated. Specifically, we examine to what extent individuals gain or lose from relaxing...

We compare integration of economic, matching and networking markets. There can be losers from integration in all three cases, but their relative numbers depend on the type of market. There can be many losers from integration of pure exchange economies. There are relatively few losers from...

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...