Interest rate bounds and fiscal policy

When the monetary authority controls the short-term interest rate we find that under a regime of permanent (and even persistent but temporary) deficits that a strict upper bound on the feasible interest rate sequence is present. More generally, the satisfaction of the fiscal authorityʹs present-value budget constraint in the presence of a deficit sequence, means that monetary and fiscal decisions cannot be independent. This is an important caveat to the results in McCallum [J. Political Econ. 92 (1984) 123].