Optimal Intermediation Under Aggregate Consumption Uncertainty

The paper develops a banking framework where a welfare comparison is made between non-tradable demand deposit and equity contracts. Contrary to the existing literature that relies heavily on smooth preferences assumption to justify the liquidity insurance superiority of the ‘run-prone’ debt contracts over the ‘run-free’ equity contracts, the paper shows that when aggregate consumption uncertainty is introduced, the welfare dominance of deposit contracts emerges for a simpler preference structure as deposit contracts offer more risk-sharing opportunities. The model illustrates that such uncertainty creates a high dispersion between the allocations that can be attained by trading in the secondary market, and therefore the equity contract provides ex ante less risk-sharing to risk-averse consumers than a tailored-made debt contract.