Bank runs are a feature of how banks get their money, John Cochrane says, not where they invest their money:
So a better approach, in my view, would be to purge the system of run-prone financial contracts — that is, fixed-value promises that are payable on demand and cause bankruptcy if not honored, like bank deposits and overnight debt. Instead, we subsidize short-term debt via government guarantees, tax deductibility, and favorable regulation, and then we try to regulate financial institutions not to overuse that which we subsidize.
[I]f we purge the system of run-prone financial contracts, essentially requiring anything risky to be financed by equity, long-term debt, or contracts that allow suspension of payment without forcing the issuer to bankruptcy, then we won’t have runs, which means we won’t have crises. People will still lose money, as they did in the tech stock crash, but they won’t react by running and forcing needless bankruptcies.