This paper develops a small New Keynesian model with capital accumulation and government debt dynamics. The paper discusses the design of simple monetary and fiscal policy rules consistent with determinate equilibrium dynamics in the absence of Ricardian equivalence. Under this assumption, government debt turns into a relevant state variable which needs to be accounted for in the analysis of eq...

The argument behind the first proposition is very general. The argument behind the second proposition is model dependent. It is exactly true in some of the simpler models we use to think about monetary policy, such as the benchmark New-Keynesian model. In that model, there is, as Jordi Gali and I have christened it, a “divine coincidence”: Stabilizing inflation in the face of either taste or te...

The fiscal position of many countries is worrying – and getting worse. Should formally independent central bankers be concerned about observed fiscal excesses spilling over to monetary policy and jeopardizing price stability? To provide some insights, this paper tracks the interactions between fiscal and monetary policies in the data across time and space. It makes three main contributions. The...

Maintaining price stability requires not only commitment to an appropriate monetary policy rule, but an appropriate fiscal policy rule as well. Ricardian equivalence does not imply that fiscal policy is irrelevant, except in the case of a certain class of policies (“Ricardian” policies). The role of fiscal developments in inflation determination under a non-Ricardian regime is illustrated throu...

This paper studies the determinacy properties of monetary and fiscal policy rules in a small-scale New Keynesian model. We modify the standard model in two ways. First, we allow positive public debt in the steady state as in Leeper [Journal of Monetary Economics 27, 129–147 (1991)]. Second, we add rule-of-thumb consumers as in Bilbiie [Journal of Economic Theory 140, 162–196 (2008)]. Leeper stu...

Monetary and fiscal policy interactions are studied in a stochastic maximizing model. Policy is ‘active’ or ‘passive’ depending on its responsiveness to government debt shocks. Schemes for financing deficits and, therefore, the existence and uniqueness of equilibria depend on two policy parameters. The model is used to: (i) characterize the equilibria implied by various financing schemes, (ii) ...

This paper reconsiders the role of separation principles between monetary and fiscal policies which in ‘normal’ times are seen as being conducive to stable outcomes of policymaking. Such principles are discussed for both ordinary nation states (i.e. ‘single economies’, characterized by one monetary and one fiscal policy) and ‘monetary unions’ (characterized by one monetary and many fiscal polic...

This paper proposes a theory of the fiscal foundations of inflation based on imperfect knowledge and learning. The theory is similar in spirit to, but distinct from, unpleasant monetarist arithmetic and the fiscal theory of the price level. Because the assumption of imperfect knowledge breaks Ricardian equivalence, details of fiscal policy, such as the average scale and composition of the publi...