The problem of efficient sharing of a resource is nearly ubiquitous. Except for pure public goods, each agent's use creates a negative externality; often the negative externality is so strong that efficient sharing is impossible in the short run. We show that, paradoxically, the impossibility of...

This paper reports on experimental tests of an instantiation of the Lucas asset pricing model with heterogeneous agents and time-varying private income streams. Central features of the model (infinite horizon, perishability of consumption, stationarity) present difficult challenges and require a...

Much of the lending in modern economies is secured by some form of collateral; residential and commercial mortgages and corporate bonds are familiar examples. This paper builds an extension of general equilibrium theory that incorporates durable goods, collateralized securities and the...

In many online systems, individuals provide services for each other; the recipient of the service obtains a benefit but the provider of the service incurs a cost. If benefit exceeds cost, provision of the service increases social welfare and should therefore be encouraged but the individuals...