We show that (i) dynamic inefficiency may be empirically relevant in a modified Diamond model with imperfect competition, (ii) if fiscal policy is used to avoid inefficiency and maintain an optimal capital intensity, the required debt ratio will be inversely related to the growth rate, and (iii)...

This paper examines the implications of different monetary and fiscal policy rules in an economy characterized by Harrodian instability. We show that (i) a monetary rule along Taylor lines can be stabilizing for low debt ratios but becomes de-stabilizing if the debt ratio exceeds a certain...