The Problem with Negative Fed Interest Rates

Neil Irwin had a piece in the Upshot section of the NYT raising the possibility that the Fed could have negative interest rates on reserves, rather than its current near zero rate, as a way to provide an additional boost to the economy. The argument is that it is very inconvenient to carry cash, so deposits would not flee banks even if the interest rate were a small negative number.

The problem is that this analysis does not consider the realities of the banked population. Banks have millions...