FEDERAL RESERVE BANK OF SAN FRANCISCO About
the Fed
News and
Events
Economic
Research
Community
Development
Banking
Info
For
Consumers
For
Educators
For Financial
Institutions
 

Economic Research

Zheng Liu

Research Advisor
Macroeconomic Research

(415) 974-3328

» CV

Research interests:
Macroeconomics
Monetary economics

Current Unpublished Working Papers

Sources of the Great Moderation: Shocks, Friction, or Monetary Policy?
2009-01 :: With Waggoner and Zha :: January 2009

+ abstract
We study the sources of the Great Moderation by estimating a variety of medium-scale DSGE models that incorporate regime switches in shock variances and in the inflation target. The best-fit model, the one with two regimes in shock variances, gives quantitatively different dynamics in comparison with the benchmark constant-parameter model. Our estimates show that three kinds of shocks accounted for most of the Great Moderation and business-cycle fluctuations: capital depreciation shocks, neutral technology shocks, and wage markup shocks. In contrast to the existing literature, we find that changes in the inflation target or shocks in the investment-specific technology played little role in macroeconomic volatility. Moreover, our estimates indicate much less nominal rigidities than those suggested in the literature.

Do Nominal Rigidities Matter for the Transmission of Technology Shocks?
2008-30 :: With Phaneuf :: November 2008

+ abstract
A commonly held view is that nominal rigidities are important for the transmission of monetary policy shocks. We argue that they are also important for understanding the dynamic effects of technology shocks, especially on labor hours, wages, and prices. Based on a dynamic general equilibrium framework, our closed-form solutions reveal that a pure sticky-price model predicts correctly that hours decline following a positive technology shock, but fails to generate the observed gradual rise in the real wage and the near-constance of the nominal wage; a pure sticky-wage model does well in generating slow adjustments in the nominal wage, but it does not generate plausible dynamics of hours and the real wage. A model with both types of nominal rigidities is more successful in replicating the empirical evidence about hours, wages and prices. This finding is robust for a wide range of parameter values, including a relatively small Frisch elasticity of hours and a relatively high frequency of price reoptimization that are consistent with microeconomic evidence.

Temptation and Self-Control: Some Evidence and Applications
FRB Minneapolis Staff Report 367 :: With Huang and Zhu :: January 2006

+ abstract
This paper studies the empirical relevance of temptation and self-control using household-level data from the Consumer Expenditure Survey. We estimate an infinite-horizon consumption-savings model that allows, but does not require, temptation and self-control in preferences. To help identify the presence of temptation, we exploit an implication of the theory that a tempted individual has a preference for commitment. In the presence of temptation, the cross-sectional distribution of the wealth-consumption ratio, in addition to that of consumption growth, becomes a determinant of the asset-pricing kernel, and the importance of this additional pricing factor depends on the strength of temptation. The estimates that we obtain provide statistical evidence supporting the presence of temptation. Based on our estimates, we explore some quantitative implications of this class of preferences on equity premium and on the welfare cost of business cycles.

Published Articles (Refereed Journals and Volumes)

Asymmetric Expectation Effects of Regime Shifts in Monetary Policy
Forthcoming in Review of Economic Dynamics :: With Waggoner and Zha

+ abstract
This paper addresses two substantive issues: (1) Does the magnitude of the expectation effect of regime switching in monetary policy depend on a particular policy regime? (2) Under which regime is the expectation effect quantitatively important? Using two canonical DSGE models, we show that there exists asymmetry in the expectation effect across regimes. The expectation effect under the dovish policy regime is quantitatively more important than that under the hawkish regime. These results suggest that the possibility of regime shifts in monetary policy can have important effects on rational agents' expectation formation and on equilibrium dynamics. They offer a theoretical explanation for the empirical possibility that a policy shift from the dovish regime to the hawkish regime may not be the main source of substantial reductions in the volatilities of inflation and output.

Learning, Adaptive Expectations, and Technology Shocks
Forthcoming in The Economic Journal :: With Huang and Zha

+ abstract
This study explores the macroeconomic implications of adaptive expectations in a standard growth model. We show that the self-confirming equilibrium under adaptive expectations is the same as the steady-state rational expectations equilibrium for all admissible parameter values, but that dynamics around the steady state are substantially different between the two equilibria. The differences are driven mainly by the dampened wealth effect and the strengthened intertemporal substitution effect, not by escapes emphasized by Williams (2003).  Consequently, adaptive expectations can be an important source of frictions that amplify and propagate technology shocks and seem promising for generating plausible labor market dynamics.

Gains from International Monetary Policy Coordination: Does It Pay to Be Different?
Journal of Economic Dynamics and Control 32(7), July 2008, 2,085-2,117 :: With Pappa

+ abstract
In a two country world where each country has a traded and a nontraded sector and each sector has sticky prices, optimal independent policy in general cannot replicate the natural-rate allocations. There are potential welfare gains from coordination since the planner under a cooperating regime internalizes a terms-of-trade externality that independent policymakers overlook. If the countries have symmetric trading structures, however, the gains from coordination are quantitatively small. With asymmetric trading structures, the gains can be sizable since, in addition to internalizing the terms-of-trade externality, the planner optimally engineers a terms-of-trade bias that favors thecountry with a larger traded sector.

Investment-Specific Technological Change, Skill Accumulation, and Wage Inequality
Review of Economic Dynamics 11(2), April 2008, 314-334 :: With He

+ abstract
Wage inequality between education groups in the United States has increased substantially since the early 1980s. The relative number of college-educated workers has also increased dramatically in the postwar period. This paper presents a unified framework where the dynamics of both skill accumulation and wage inequality arise as an equilibrium outcome driven by measured investment-specific technological change. Working through equipment-skill complementarity and endogenous skill accumulation, the model does well in capturing the steady growth in the relative quantity of skilled labor during the postwar period and the substantial rise in wage inequality after the early 1980s. Based on the calibrated model, we examine the quantitative effects of some hypothetical tax-policy reforms on skill accumulation, wage inequality, and welfare.

Technology Shocks and Labor Market Dynamics: Some Evidence and Theory
Journal of Monetary Economics 54(8), November 2007, 2,534-2,553 :: With Phaneuf

+ abstract
A positive technology shock may lead to a rise or a fall in per capita hours, depending on how hours enter the empirical VAR model. We provide evidence that, independent of how hours enter the VAR, a positive technology shock leads to a weak response in nominal wage inflation, a modest decline in price inflation, and a modest rise in the real wage in the short run and a permanent rise in the long run. We then examine the ability of several competing theories to account for this VAR evidence. Our preferred model features sticky prices, sticky nominal wages, and habit formation. The same model also does well in accounting for the labor market evidence in the post-Volcker period.

Business Cycles with Staggered Prices and International Trade in Intermediate Inputs
Journal of Monetary Economics 54(4), May 2007, 1,271-1,289 :: With Huang

+ abstract
International trade in intermediate inputs and, increasingly, in goods produced at multiple stages of processing has been widely studied in the real trade literature. We assess the role of this feature of modern world trade in accounting for some stylized facts about international business cycles. Our model with staggered prices and trade in intermediates across four stages of processing does well in explaining the observed international correlations in aggregate quantities, and it performs much better than a single-stage model with no trade in intermediates. The model in itself does not provide a full account of the cyclical behavior of the real exchange rate, but, compared to the single-stage model, it moves in the right direction.

Sellers' Local Currency Pricing or Buyers' Local Currency Pricing: Does It Matter for International Welfare Analysis?
Journal of Economic Dynamics and Control 30(7), July 2006, 1,183-1,213 :: With Huang

+ abstract
We study international transmissions and welfare implications of monetary shocks in a two-country world with multiple stages of production and multiple border-crossings of intermediate goods. This empirically relevant feature is important, as it has opposite implications for two external spillover effects of a unilateral monetary expansion. If all production and trade are assumed to occur in a single stage, the conflict-of-interest terms-of-trade effect tends to dominate the common-interest efficiency-improvement effect for reasonable parameter values, so that the international welfare effects would depend in general on the underlying assumptions about the currencies of price setting. The stretch of production and trade across multiple stages of processing magnifies the efficiency-improvement effect and dampens the terms-of-trade effect. Thus, a monetary expansion can be mutually beneficial regardless of its source or the pricing assumptions.

Inflation Targeting: What Inflation Rate to Target?
Journal of Monetary Economics 52(8), November 2005, 1,435-1,462 :: With Huang

+ abstract
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.

Does Trade Openness Matter for Aggregate Instability?
Journal of Economic Dynamics and Control 29(7), July 2005, 1,165-1,192 :: With De Fiore

+ abstract
This paper presents a cash-in-advance model of a small open economy and shows that whether an inflation-targeting interest rate rule introduces aggregate instability depends in general on the degree of openness to international trade. This result emerges regardless of whether prices are sticky or flexible. In a closed economy, as the monetary authority responds to movements in inflation, the resulting changes in interest rates affect aggregate consumption through an intertemporal substitution effect and an inflation tax effect. In a small open economy, this policy also induces changes in the terms of trade, which, depending on the degree of openness, can generate counteracting effects on consumption. As a consequence, the implications of interest rate rules on macroeconomic stability in an open economy differ from those in a closed economy.

Why Does the Cyclical Behavior of Real Wages Change Over Time?
American Economic Review 94(4), September 2004, 836-856 :: With Huang and Phaneuf

+ abstract
The cyclical behavior of real wages has evolved from mildly countercyclical during the interwar period to modestly procyclical in the postwar era. This paper presents a general equilibrium business-cycle model that helps explain the evolution. In the model, changes in the real wage cyclicality arise from interactions between nominal wage and price rigidities and an evolving input-output structure.

Input-Output Structure and Nominal Rigidity: The Persistence Problem Revisited
Macroeconomic Dynamics 8(2), April 2004, 188-206 :: With Huang

+ abstract
This paper revisits an important issue concerning the persistent real effect of a shock to monetary policy. Although recent sentiment has shifted away from price stickiness toward wage stickiness in explaining persistence, the present paper shows that introducing an input output structure tends to make the former an equally important monetary transmission mechanism. Under staggered wage setting, the well-known relative-wage effect is the only source of endogenous sluggishness in wage, and thus price, adjustments, regardless of whether there is an intermediate input. Under staggered price setting, relative wages are constant, but the presence of an intermediate input creates a real-wage effect that prevents nominal wages from deviating too much from a sticky intermediate-input price. Meanwhile, stickiness in the intermediate-input price translates directly into sluggishness in marginal-cost movement. This reinforces the endogenous rigidity in the nominal wages and makes firms pricing decisions even more rigid. Thus, although it makes no difference in output dynamics under staggered wage setting, the input output structure improves the ability of staggered price setting in generating persistence. As a consequence, the conventional wisdom on the equivalence of price and wage staggering may continue to hold for some reasonable parameter values.

Staggered Price-Setting, Staggered Wage-Setting, and Business Cycle Persistence
Journal of Monetary Economics 49(2), March 2002, 405-433 :: With Huang

Production Chains and General Equilibrium Aggregate Dynamics
Journal of Monetary Economics 48(2), October 2001, 437-462 :: With Huang

Seasonal Cycles, Business Cycles, and Monetary Policy
Journal of Monetary Economics 46(2), October 2000, 441-464