Government Debt, Budget Surplus, and Popularity of Politicians

This paper sets up a positive model of government behavior to determine the optimal fiscal policy of a politician who aims to reach a certain target level of national debt and remain popular at the same time. We model explicitly the response of the citizens to the fiscal policy set by the politician. To that end, we assume that citizens form an equilibrium acceptance rate of savings and adjust dynamically this savings rate to the currently prevailing levels of government debt and primary surplus. The difference between the equilibrium acceptance rate of savings as formed by the public and the fiscal policy actually chosen by the politician determines the politician popularity. Using the Pontryagin maximum principle, we derive the optimal level of the fiscal policy and investigate its local stability depending on the parameters of the model. We show that cyclical strategies that is, phases of saving (primary surplus) and spending (primary deficit)], may be optimal.