Intergenerational Risk Sharing, Stability and Optimality of Alternative Pension Systems

In an analysis of the risk-sharing properties of different types of pension systems, we show that only a fixed-fee pay-as-you-go (PAYG) pension systems can provide intergenerational risk sharing for living individuals. Under some circumstances, however, other PAYG pension systems can enhance the expected welfare of all generations by reducing intergenerational income variability. We derive conditions for this to occur. We also analyze the stability of actuarially fair PAYG pension systems.