I examine the title question in a competitive framework where the tran
saction demand for money is modeled using a cash-in-advance constraint
and only distortionary taxes are possible. Empirical evidence and sim
ulations are used to document the plausibility of the assumptions whic
h produce the Friedman rule; these findings suggest that it is not a g
ood benchmark. My results suggest that an optimal monetary policy call
s for nominal interest rates that can exceed 6% per year.