Uncertainty and nonlinear macroeconomic effects of fiscal policy in the US: a SEIVAR-based analysis

Purpose - The purpose of this paper is to investigate whether the macroeconomic effects of government spending shocks vary with the degree of macroeconomic uncertainty. Design/methodology/approach - The authors use quarterly US data from 1960 to 2017 and employ the Self-Exciting Interacted VAR (SEIVAR) to compute nonlinear generalized impulse response functions (GIRFs) to an orthogonalized government spending shock during tranquil and in uncertain times. The parsimonious design of the SEIVAR enables us to focus on extreme deciles of the uncertainty distribution and to control for the financing side of the government budget, monetary policy, financial frictions and consumer confidence. Findings - Fiscal spending has positive output effects in tranquil times, but is contractionary during times of heightened macroeconomic uncertainty. The results indicate an important role of the endogenous response of macroeconomic uncertainty. Investigating different government spending purposes, only increases in research and development expenditures reduce uncertainty and boost output during uncertain times. Originality/value - The authors contribute to the literature in using a method which allows to control for a large set of confounding factors and accounts for the uncertainty response.