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

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)

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

Multiple stages of processing and the quantity anomaly in international business cycle models.

We construct a two-country DSGE model with multiple stages of processing and local-currency staggered price-setting to study cross-country quantity correlations driven by monetary shocks. The model embodies a mechanism that propagates a monetary surprise in the home country to lower the foreign price level while restraining the home price level from rising too quickly. It does so through reducing material costs in terms of the foreign currency unit while dampening the upward movements in the costs in terms of the home currency unit, both in absolute terms and relative to the costs of primary factors. We show that, through this mechanism and a resulting factor substitution effect, the model is able to generate significant cross-country quantity correlations, with correlations in consumption considerably lower than correlations in output, as in the data.Business cycles

Temptation and self-control: some evidence and applications

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.Asset pricing ; Welfare

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

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