This paper re-evaluates the Diamond-Dybvig analysis of deposit insurance by
constructing a model in which an agent not in need of liquidity sets up a
financial intermediary to sell liquidity insurance to other agents who desi
re such insurance. This intermediary resembles a real-world bank in that it
is financed by both demand deposits and equity. It also dominates the Diam
ond-Dybvig intermediary, which is funded only by demand deposits. Provided
the intermediary has adequate capital, it also is perfectly safe. Deposit i
nsurance then is both unnecessary and incapable of achieving a superior out
come to that which private agents could achieve on their own.