Revisiting the fiscal theory of sovereign risk from a DSGE viewpoint

In this study, we revisit Uribe’s (2006) “fiscal theory of sovereign risk”, which suggests a trade-off between stabilizing inflation and suppressing default. Unlike Uribe (2006), we develop a class of dynamic stochastic general equilibrium models in which the production is endogenous with nominal rigidities but whereby the default mechanism follows Uribe (2006). This marginal change generates the New Keynesian Phillips curve that connects inflation and the output gap. Under the optimal monetary and fiscal (OMF) policy, the nominal interest rate and tax rate are both used as policy instruments. A change in the tax rate stabilizes inflation by stabilizing the output gap. Furthermore, this change in the tax rate stabilizes fiscal surplus. Therefore, a trade-off between stabilizing inflation and suppressing default is mitigated by the OMF policy. Note that the OMF policy is a de facto inflation stabilization policy; thus, the tax rate is viewed as a policy instrument for stabilizing inflation.