Sharing, Time Diversification and

Abstract. One of the most enduring topics in financial theory is the persistence of investment risk across time. Traditional finance lacks methods for considering and hedging non-diversifiable risks. This pa-per is based on the general equilibrium model of Allen and Gale (1997). We extend their model in various directions: the intermediary is a firm and not a planner, financial markets are assumed to be incomplete, and the mechanism of intergenerational risk-sharing is endogenously deter-mined. Our model allows for the analysis of optimal behavior of indi-viduals and the intermediary together with the respective feedback pro-cesses