Why do governments end up with debt ? Short-run effects matter

This paper reconsiders the impact of public debt in an economy with heterogeneous households and incomplete markets to emphasize the short-run effects of an increase in public debt. As compared to models that rest on steady-state analysis, we show that the welfare gains of a public debt increase are substantially higher when transitional dynamics are accounted for. The additional debt issue allows for a temporary reduction in the income tax rate, which stimulates labor supply and generates an overshooting of the interest rate. The short-run gains create a temptation to deviate toward higher levels of debt. Debt increases continue to generate welfare gains even when debt is considerably higher than its long-run optimal level.