The equity premium in an overlapping-generations economy

In a recent paper, Constantinides, Donaldson and Mehra (CDM) present a convincing economic story that could simultaneously explain a high equity premium and a low risk-free rate. The argument is based on the effect of a borrowing restriction in an overlapping-generations model (OLG) with three generations. This paper investigates the effect of borrowing restrictions on the size of the equity premium in a model similar to CDM, but with a complete structure of contingent claims. The main conclusion of the analysis is that the results obtained by CDM follow from the particular market structure adopted in the model rather than the effects of the life cycle. Once the markets are completed, the equity premium and the risk-free rate in the OLG economy are identical to those obtained in a representative-agent (RA) economy.