Evidence for a chemical-thermal structure at base of mantle from sharp lateral P-wave variations beneath Central America

Compressional waves that sample the lowermost mantle west of Central America show a rapid change in travel times of up to 4 s over a sampling distance of 300 km and a change in waveforms. The differential travel times of the PKP waves (which traverse Earth's core) correlate remarkably well with predictions for S-wave tomography. Our modeling suggests a sharp transition in the lowermost mantle from a broad slow region to a broad fast region with a narrow zone of slowest anomaly next to the boundary beneath the Cocos Plate and the Caribbean Plate. The structure may be the result of ponding of ancient subducted Farallon slabs situated near the edge of a thermal and chemical upwelling

Staggered contracts and business cycle persistence

Staggered price and staggered wage contracts are commonly viewed as similar mechanisms in generating persistent real effects of monetary shocks. In this paper, we distinguish the two mechanisms in a general equilibrium framework. We show that, although the dynamic price setting and the dynamic wage setting equations are alike, a key parameter governing persistence is linked to the underlying preferences and technologies in different ways. Under the staggered wage mechanism, an intertemporal smoothing incentive in labor supply creates a real rigidity that is absent under the staggered price mechanism. Consequently, the two have different implications on persistence. While the staggered price mechanism by itself is incapable of, the staggered wage mechanism has a great potential in generating persistence.Business cycles

Staggered Contracts and Business Cycle Persistence

Staggered price and staggered wage contracts are commonly viewed as similar mechanisms in generating persistent real effects of monetary shocks. In this paper, we distinguish the two mechanisms in a dynamic stochastic general equilibrium framework. We show that, although the dynamic price setting and wage setting equations are alike, a key parameter governing persistence is linked to the underlying preferences and technologies in different ways. Under the staggered wage mechanism, an intertemporal smoothing incentive in labor supply creates a real rigidity that is absent under the staggered price mechanism. Consequently, the two mechanisms have different implications on persistence. While the staggered price mechanism by itself does not contribute to, the staggered wage mechanism plays an important role in generating persistence.Staggered Contracts; Business Cycle Persistence; Monetary Policy

Chain of Production as a Monetary Propagation Mechanism

This paper studies a general equilibrium model with multiple stages of production and sticky prices. Working through the input-output relations among industries at different stages and the timing of firms' pricing decisions, the model generates persistent fluctuations in both the inflation rate and aggregate output following a monetary shock. The persistence is larger, the greater the number of production stages. With a sufficient number of stages, the real persistence is arbitrarily large.Chain of Production; Persistence; Monetary Policy

Production interdependence and welfare

The international welfare effects of a country's monetary policy shocks have been controversial in the new open economy macro (i.e., NOEM) literature. While a unilateral monetary expansion increases the production efficiency in each country, it affects the terms of trade in favor of one country against another depending on the currencies of price setting. In this paper, we incorporate multiple stages of production and trade into a standard NEOM model to capture world production interdependence, and show that increased world production interdependence tends to magnify the e±ciency-improvement effect while dampening the terms-of-trade effect. As a consequence, a unilateral monetary expansion can be mutually beneficial regardless of in which currency prices are set. In this sense, international monetary policy transmission may not be a source of potential conflict in a world with production interdependence. JEL Classification: E32, F31, F41Local currency pricing, Monopolistic competition, Stages of processing, Welfare

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.Inflation (Finance)

Vertical International Trade as a Monetary Transmission Mechanism in an Open Economy

This paper analyzes a two-country general equilibrium model with multiple stages of production and sticky prices. Working through the cross-country input-output relations and endogenous price stickiness, the model generates the observed patterns in international aggregate comovements following monetary shocks. In particular, both output and consumption comove across countries, and output correlation is larger than consumption correlation, as in the data. The model also generates persistent fluctuations of real exchange rates. Thus, vertical international trade plays an important role in propagating monetary shocks in an open economy.Vertical International Trade; Monetary Policy; International Comovements; Real Exchange Rate Persistence

Chain of production as a monetary propagation mechanism

This paper studies a general equilibrium model with multiple stages of production and asynchronized price setting that provides a new explanation for the observed persistent real effects of monetary shocks. The key feature of the model is a vertical chain-of-production structure. In this model, the effects of monetary shocks on price adjustment are gradually dampened via the interactions of firms through their input-output relations and the timing of their price decisions. The model predicts that prices adjust by a smaller amount and less rapidly at later stages than at earlier stages, which is supported by empirical evidence. More importantly, an increase in the total number of stages in the model leads to not only uniformly larger and longer-lasting real effects but also flatter paths of aggregate output response. With sufficiently many stages, the price level adjustment becomes arbitrarily close to zero and the aggregate output tends to carry the full burden of adjustment. Thus, the chain-of-production mechanism goes a long way in propagating the shocks.Econometric models