Real Wage Rigidities and the New Keynesian Model

Most central banks perceive a trade-off between stabilizing inflation and stabilizing the gap between output and desired output. However, the standard new Keynesian framework implies no such trade-off. In that framework, stabilizing inflation is equivalent to stabilizing the welfare-relevant output gap. In this paper, we argue that this property of the new Keynesian framework, which we call the divine coincidence , is due to a special feature of the model: the absence of nontrivial real imperfections. We focus on one such real imperfection, namely, real wage rigidities. When the baseline new Keynesian model is extended to allow for real wage rigidities, the divine coincidence disappears, and central banks indeed face a trade-off between stabilizing inflation and stabilizing the welfare-relevant output gap. We show that not only does the extended model have more realistic normative implications, but it also has appealing positive properties. In particular, it provides a natural interpretation for the dynamic inflation–unemployment relation found in the data.     

How Do Nominal and Real Rigidities Interact? A Tale of the Second Best

This paper analyzes the importance of real wage rigidities, in particular through their interaction with price stickiness, in a New Keynesian model. Real wage rigidities result from a combination of staggered wage setting and partial indexation of nonreset wages to past inflation. Blanchard and Galí (2007) show real rigidities to introduce a trade‐off between stabilizing inflation and the welfare‐relevant output gap. The present paper complements their findings by showing that the welfare costs of real rigidities can be substantial compared to nominal frictions. In a typical “tale of the second best,” we also show that in the presence of real wage rigidities, higher price stickiness can be welfare enhancing.     

Real Wage Rigidities and the Cost of Disinflations

This paper analyzes the cost of disinflations under real wage rigidities in a micro-founded New Keynesian model. The conventional view is that real wage rigidities can be a useful mechanism to generate a slump in output after a credible disinflationary policy because they prevent the immediate adjustment of inflation. This view is flawed, since it depends on analyzing the model in a linearized framework. Once nonlinearities are taken into account, the results change both qualitatively and quantitatively. Disinflations actually lead to a permanently higher level of output, and real wage rigidities increase the output during the adjustment to the new steady state.     

The Role of Real Wage Rigidity and Labor Market Frictions for Inflation Persistence

We analyze the transmission mechanism of wages to inflation within a New Keynesian business cycle model with wage rigidities and labor market frictions. Our main focus is on the channel of real wage rigidities on inflation persistence for which we find the specification of the wage bargaining process to be of crucial importance. Under the standard efficient Nash bargaining, the feedback of wage rigidities on inflation is ambiguous and depends on other labor market variables. However, under the alternative right‐to‐manage bargaining we find that more rigid wages translate directly into more persistent movements of aggregate inflation.     

Inflation targeting: What inflation rate to target?

In an economy with nominal rigidities in both an intermediate good sector and a finished good sector, and thus with a natural distinction between CPI and PPI inflation rates, a benevolent central bank faces a tradeoff between stabilizing the two measures of inflation, a final output gap and, unique to our model, a real marginal cost gap in the intermediate sector, so that optimal monetary policy is second-best. We discuss how to implement the optimal policy with minimal information requirement and evaluate the robustness of these simple rules when the central bank may not know the exact sources of shocks or nominal rigidities. A main finding is that a simple hybrid rule under which the short-term interest rate responds to CPI inflation and PPI inflation results in a welfare level close to the optimum, whereas policy rules that ignore PPI inflation or PPI sector shocks can result in significant welfare losses.     

On Targeting Frameworks And Optimal Monetary Policy

We show that speed limit policy, a monetary policy strategy that focuses on stabilizing inflation and the change in the output gap, consistently outperforms flexible inflation targeting and flexible price level targeting in empirical medium‐scale DSGE models under discretionary policymaking. In contrast to small‐scale New Keynesian models, this welfare ranking of the targeting frameworks is not overturned when inflation dynamics are mostly backward‐looking. Importantly, the performance of the speed limit policy shows less sensitivity to its parameterization than other frameworks that target the inflation rate or the price level.     

The Interaction of Monetary and Macroprudential Policies

I analyze a New Keynesian dynamic stochastic general equilibrium (DSGE) model where the financing of productive investment is affected by a moral hazard problem. I solve for jointly Ramsey‐optimal monetary and macroprudential policies. I find that when a financial friction is present in addition to the standard nominal friction, the optimal policy can replicate the first‐best allocation if the social planner can conduct both monetary and macroprudential policy. Using monetary policy alone is not enough: a policy trade‐off between stabilizing inflation and output gap emerges. When policy follows simple rules, the source of fluctuations is relevant for the choice of the appropriate policy mix.     

Optimal monetary policy with the cost channel

In the standard new Keynesian framework, an optimizing policy maker does not face a trade-off between stabilizing the inflation rate and stabilizing the gap between actual output and output under flexible prices. An ad hoc, exogenous cost-push shock is typically added to the inflation equation to generate a meaningful policy problem. In this paper, we show that a cost-push shock arises endogenously when a cost channel for monetary policy is introduced into the new Keynesian model. A cost channel is present when firms’ marginal cost depends directly on the nominal rate of interest. Besides providing empirical evidence for a cost channel, we explore its implications for optimal monetary policy. We show that its presence alters the optimal policy problem in important ways. For example, both the output gap and inflation are allowed to fluctuate in response to productivity and demand shocks under optimal monetary policy.     

Notes on the Underground: Monetary Policy in Resource‐Rich Economies

The central bank of a commodity‐exporting small open economy faces the traditional trade‐off between domestic inflation and output gap. The commodity sector introduces a terms‐of‐trade inefficiency that gives rise to an endogenous cost‐push shock, changes the target level for output, reduces the slope of the Phillips curve, and increases the importance of stabilizing the output gap. Optimal monetary policy calls for a reduction of the interest rate following a drop in the oil price. In contrast, a central bank with a mandate to stabilize consumer price inflation raises interest rates to limit the inflationary impact of an exchange rate depreciation.     

Comparing New Keynesian models of the business cycle: A Bayesian approach

The baseline New Keynesian model cannot replicate the observed persistence in inflation, output, and real wages for sensible parameter values. As a result, several extensions have been suggested to improve its fit to the data. We use a Bayesian approach to estimate and compare the baseline sticky price model of Calvo's [1983. Staggered prices in a utility maximizing framework. Journal of Monetary Economics 12, 383-398.] and three extensions. Our empirical results are as follows. First, we find that adding price indexation improves the fit of Calvo's [1983. Staggered prices in a utility maximizing framework. Journal of Monetary Economics 12, 383-398.] model. Second, models with both staggered price and wage setting dominate models with only price rigidities. Third, introducing wage indexation does not significantly improve the fit. Fourth, all model estimates suggest a high degree of price stickiness. Fifth, the estimates of labor supply elasticity are higher in models with both staggered price and wage contracts. Finally, the estimated inflation parameters of the Taylor rule are stable across models.     

Price Stability in Economies with Habit Persistence

This paper shows that the divine‐coincidence does not hold in a sticky price model with external habit if a time‐varying tax rate on labor income is not implemented to fully eliminate the time‐varying distortions associated with external habit and monopoly power in goods market. The required labor income tax rate is inversely related to the risk‐free real interest rate and the markup in the goods market, but it is proportional to the degree of external habit. Under this circumstance, the optimal monetary policy commands a countercyclical interest rate, having a perfect negative correlation with tax rate in the sticky price model with external habit. If a time‐invariant tax is the only fiscal instrument, then the degree of external habit entails a gap between the private marginal rate of substitution between consumption and labor and the social marginal rate of substitution, generating an endogenous trade‐off between the stabilization of welfare‐relevant output gap and inflation. Under this circumstance, price stability is not the optimal policy. The monetary policy authority should optimally try to undo the time‐varying distortions associated with external habit and monopoly power in goods market by deviating from price stability.     

New measures of the output gap based on the forward-looking new Keynesian Phillips curve

Forward-looking versions of the New Keynesian Phillips curve imply that the output gap, the deviation of the actual output from its natural level due to nominal rigidities, drives the dynamics of inflation relative to expected inflation. We exploit this to set up a bivariate unobserved component model for extracting new estimates of the output gap in the US. The gap estimates are large and persistent even after allowing for correlated trend and cycle shock. We then augment our model to use the information in the unemployment rate. The estimates confirm the presence of a large and persistent cyclical component.     

Banking Competition,Collateral Constraints,and Optimal Monetary Policy

We analyze optimal monetary policy in a model with two distinct financial frictions: monopolistically competitive banks that charge endogenous lending spreads, and collateral constraints. We show that welfare maximization is equivalent to stabilization of four goals: inflation, output gap, the “consumption gap” between borrowers and savers, and a “housing gap” that measures the distortion in the distribution of the collateralizable asset between both groups. Collateral constraints create a trade‐off between stabilization goals. Following both productivity and financial shocks, and relative to strict inflation targeting, the optimal policy implies sharper movements in the policy rate, aimed primarily at reducing fluctuations in asset prices and hence in borrowers' net worth. The policy trade‐offs become amplified as banking competition increases, due to the fall in lending spreads and the resulting increase in borrowers' leverage.     

Optimal monetary policy in a small open economy with staggered wage and price contracts

We study optimal monetary policy for a small open economy in a model where both domestic prices and wages are sticky due to staggered contracts. The simultaneous presence of the two forms of nominal rigidities introduces an additional trade-off between domestic inflation and the output gap. We derive a second-order approximation to the average welfare losses that can be expressed in terms of the unconditional variances of the output gap, domestic price inflation, and wage inflation. As a consequence, the optimal policy seeks to minimize a weighted average of these variances. We analyze welfare implications of several alternative simple policy rules, and find that domestic price inflation targeting generates relatively large welfare losses, whereas CPI inflation targeting performs nearly as well as the optimal rule.     

Non-Atomistic Wage Setters and Monetary Policy in a New Keynesian Framework

This paper extends an otherwise standard New Keynesian (NK) model to allow for the presence of large wage setters. Building on monetary models from an earlier generation, I contribute to the NK literature by adding some new insight. It is shown that once the presence of large wage setters is taken into account, the degree of wage setting centralization and the aggressiveness of the central bank in stabilizing inflation jointly affect steady state employment. Because of this interaction, the benefits associated with inflation stabilization increase in the centralization of the wage bargaining process.     

Monetary Policy and the Asset Risk‐Taking Channel

How important is the risk‐taking channel for monetary policy? To answer this question, we develop and estimate a quantitative monetary DSGE model where banks choose excessively risky investments, due to an agency problem that distorts banks' incentives. As the real interest rate declines, these distortions become more important and excessive risk taking increases, lowering the efficiency of investment. We show theoretically that this novel transmission channel generates a new monetary policy trade‐off between inflation and real interest rate stabilization, whereby the central bank may prefer to tolerate greater inflation volatility in order to lower excessive risk taking.     

Trend Inflation and the Nature of Structural Breaks in the New Keynesian Phillips Curve

We show that with a unit root in inflation, the new Keynesian Phillips curve (NKPC) implies an unobserved components model with a stochastic trend component and an inflation gap. Our empirical results suggest that with an increase in trend inflation during the Great Inflation, the response of inflation to real economic activity decreases and the persistence of the inflation gap increases due to an increase in the persistence of the unobserved stationary component. These results are in line with the predictions of Cogley and Sbordone ( 2008 ), who show that the coefficients of the NKPC are functions of time‐varying trend inflation.     

Lack of divine coincidence in New Keynesian models

The literature has long agreed that the divine coincidence holds in standard New Keynesian models: the monetary authority is able to simultaneously stabilize inflation and output gap in response to preference and technology shocks. I show that the divine coincidence holds only when inflation is stabilized at exactly zero. Even small deviations from zero generate policy trade-offs. I demonstrate this result using the model׳s non-linear equilibrium conditions to avoid biases from log-linearization. When the model is log-linearized, a non-zero steady state level of inflation gives rise to what I call the endogenous trend inflation cost-push shock in the New -Keynesian Phillips curve.     

Trend inflation, wage and price rigidities, and productivity growth

What are the steady-state implications of inflation in a general-equilibrium model with real per capita output growth and staggered nominal price and wage contracts? Surprisingly, a benchmark calibration implies an optimal inflation rate of -1.9 percent. The analysis also shows that trend inflation has important effects on the economy when combined with nominal contracts and real output growth. Steady-state output and welfare losses are quantitatively important even for low values of trend inflation. Further, nominal wage contracting is found to be quantitatively more important than nominal price contracting in generating the results. This conclusion does not arise from price dispersion per se, but from an effect of nominal output growth on the optimal markup of monopolistically competitive labour suppliers. Finally, accounting for productivity growth is found to be important for calculating the welfare costs of inflation. Indeed, the presence of 2 percent productivity growth increases the welfare costs of inflation in the benchmark specification by a factor of four relative to the no-growth case.