It may seem an odd time to suggest that US banks should be allowed to become bigger. After all, dismantling institutions deemed too big to fail is often suggested as one way to stop financial crises happening again. Nevertheless, lifting a cap that limits US banks to 10 per cent of domestic deposits is a sensible idea.

Motivated by political aversion to large interstate entities as much as well-thought out competition concerns, the threshold seemed distant when first introduced in 1994. Now three banks – Bank of America, JPMorgan Chase and Wells Fargo – are near or even exceed it.