Social learning expectations: microfoundations and a Dynare toolboxJoint with Isabelle SALLE (University of Ottawa and University of Amsterdam) andGauthier VERMANDEL (École Polytechnique and Paris-Dauphine University).submitted
Social learning (SL) is a behavioral model in which expectations and the resulting aggregate dynamics stem from the interactions of a large amount of heterogeneous agents. Nonetheless, this framework has so far lacked micro-foundations and a general-solution method. This paper bridges these two gaps with: (i) a micro-founded New Keynesian model with social learning expectations; (ii) a general solution method that we implement in a Dynare toolbox that solves any linear state-space model with SL expectations. The resulting framework provides a self-contained tool to contrast policy analysis under SL and rational expectations. As an illustration, optimal monetary policy rules are studied under the two expectation regimes.
Unemployment risk and discretionary fiscal spendingsubmitted
This paper studies the effects of discretionary fiscal policy responses to adverse aggregate shocks. For this, I build a tractable model where households face idiosyncratic unemployment risk in a Search-and-Matching (SaM) labor market with explicit intensive and extensive employment margins. Focusing on the spending side of fiscal stimuli, I investigate transitory increases in Unemployment Insurance (UI) benefits and public purchases. I show that the effects of transitory increases in fiscal spending largely depend on the state of the labor market and the type of adverse shock hitting the economy. At the aggregate level, the most welfare-improving fiscal stimuli appear to be rather small and over a long period. At the idiosyncratic level, welfare improvements are very unequally distributed. Front-loaded increases in fiscal spending may run into supply constraints and have important undesirable consequences. Fiscal stimuli through UI transfers are never Pareto efficient whereas fiscal stimuli through public purchases can be.
Precautionary saving and un-anchored expectations
(previously titled : Learning and supply shocks in a HANK economy)
This paper investigates monetary policy in a heterogeneous agent new Keynesian (HANK) model where agents face idiosyncratic income risk and use adaptive learning in order to form their expectations. Households experience different histories and observe different idiosyncratic variables. This gives rise to idiosyncratic learning processes, which naturally implies the existence of heterogeneous expectations. In HANK models, supply shocks generate precautionary saving. The learning setup amplifies this effect and can result in long-lasting disinflationary traps. Dovish Taylor rules focused on closing the output gap dampen the learning effects. Price level targeting improves the inflation and output stabilization trade-off by better anchoring expectations.
Price setting frequency and the Phillips curveJoint with Emanuel GASTEIGER (TU Wien).submitted
We develop a New Keynesian (NK) model with endogenous price setting frequency. Whether a firm updates its price is a discrete choice: when expected benefits outweigh expected costs, prices are reset optimally. The model gives rise to a non-linear Phillips curve as prices are more flexible during demand-driven expansions and less so during demand-driven recessions. Monetary policy can have substantial real effects despite the model having a state-dependent pricing component. Our quantitative analysis shows that contrary to the standard NK model, the assumed price setting behaviour: (i) is consistent with micro data on price setting frequency; (ii) generates a direct effect of the time-varying price setting frequency on inflation; (iii) creates time-variation in the Phillips curve slope that explains shifts in the Phillips curve associated with different historical episodes; (iv) explains inflation dynamics without relying on implausible high cost-push shocks and nominal rigidities inconsistent with micro data; (v) reconciles the NK model with observed inflation moments.
Social learning and monetary policy at the effective lower boundJoint with Jasmina ARIFOVIC (Simon Fraser University), Isabelle SALLE (University of Ottawa and University of Amsterdam) andGauthier VERMANDEL (École Polytechnique and Paris-Dauphine University).submitted
This paper develops a model that jointly accounts for the missing disinflation in the wake of the Great Recession and the subsequently observed inflation-less recovery. The key mechanism works through heterogeneous expectations that may durably lose their anchoring to the central bank (CB)'s target and coordinate on particularly persistent below-target paths. The welfare cost associated with persistent low inflation may be reduced if the CB announces to the agents its target or its own inflation forecasts, as communication helps coordinate expectations. However, the CB may lose its credibility whenever its announcements become decoupled from actual inflation.
Work in progress:
Equilibrium selection and idiosyncratic information set in an Aiyagari economy
Inflation target and misspecified equilibrium at the effective lower bound