On the (de)stabilization role of protectionism: Theory and evidence

To what extent protectionism affects growth and (de)stabilizes the economies? Since 2018, some countries have resorted to protectionist measures as the United States. Although the impacts of protectionism on growth have been widely explored without reaching a consensus, few has been said on its impacts on macroeconomic stability. The present paper attempts to gauge more precisely its implications using a Barro-type (1990) endogenous growth model with public debt and credit constraint where tariffs are a proxy of protectionism. Our main result is to show that when the debt level is high, and the share of foreign goods in total consumption is large enough, increasing tariffs may have a dramatic destabilizing effect generating some expectation coordination failure between multiple equilibria and the possible existence of large self-fulfilling fluctuations. We also exhibit some trade-off between tariffs and growth as tariffs are beneficial only to the low growth equilibrium which may only appear in the globally indeterminate case. We also propose some numerical illustrations confirming the destabilizing impact of tariffs in the case of the US economy. We finally propose an Event Study analysis to confront our results. While our effects appear short lasting, two quarters, we show that the implementation of protectionism destabilizes the US economy in the short run.