When infinite-lived agents trade long-lived assets secured by durable goods, equilibrium exists without any additional debt constraints or uniform impatience conditions on agents' characteristics. Also, price bubbles are absent when physical endowments are uniformly bounded away from zero.

We establish necessary and sufficient conditions for the individual optimality of a consumption-portfolio plan in an infinite horizon economy where agents are uniformly impatient and fiat money is the only asset available for inter-temporal transfers of wealth. Next, we show that fiat money has...