A Comparison of Debt and Primary-deficit Constraints

This paper compares constraints on the public debt with constraints on the primary deficit. The analysis takes into account how an optimizing government reacts to the different constraints when deciding on a spending and borrowing plan. We find that the economy behaves similarly under both constraints, although for our benchmark calibration welfare is higher under the debt constraint. Further, the debt constraint is more robust against changes in the interest rate. Our results lend support to the enhanced focus on the public debt after the recent reform of the Stability and Growth Pact.