Public investment, national debt, and economic growth: The role of debt finance under dynamic inefficiency

Public investment is a central issue in the dynamic analyses of fiscal policy and economic growth. Debt financing for public investment and its effects have recently received great attention because interest rates have been low, almost invariably remaining below economic growth rates. This paper presents examination of the effects of debt-financed public investment subject to a simple fiscal rule in an overlapping generations model with public capital. This topic includes capital budgeting and the debt–deficit criterion of the Maastricht treaty. We show herein that debt financing for public investment enhances economic growth if an economy is dynamically inefficient and if public capital has a sufficiently large productivity effect. Moreover, it reduces economic growth rates in a dynamically efficient economy. Debt and growth can have a monotonic or non-monotonic relation, depending on the steady-state interest rate, growth rate, and productivity effect of public investment. The findings indicate that debt–growth relations match with controversial empirical evidence. Furthermore, existing generations choose perfect debt finance if dynamic inefficiency exists. In contrast, a balanced budget is preferred in a dynamically efficient economy with low productivity effects of public capital. However, an economy with high productivity effects of public capital might cho ose debt financing. This paper contributes to the elucidation of currently emphasized issues of public investment.