Published papers

We use a residual-based bootstrap method to re-examine the finding of the Granger causality relation from exchange rates to fundamentals in Engel and West (2005), in which the relation is taken as evidence for their explanation for the present-value model for exchange rates. Our test results are against the previous findings. The Monte Carlo experiment results suggest that the previous evidence for the causality relation from exchange rates to fundamentals is very likely caused by the size distortion. Hence, the existing Granger causality evidence is not strong enough to validate the new explanation for the present-value model.

An important difficulty in many models of behavioural economics is that preferences are endogenous and unstable. Therefore, preferences may not provide the most desirable yardstick to evaluate social states. The present paper proposes unconditional love as a candidate for such a yardstick. The concept of unconditional love, although lofty, is often hard to apply for practical policy recommendations. We propose an intermediary learning stage, where learning to unconditionally love is desirable, and policies that promote such learning are deemed to be good. We illustrate the use of this principle in models of endogenous altruism.

It is well known that there is a large degree of uncertainty around Rogoff's consensus half-life of the real exchange rate. To obtain a more efficient estimator, we develop a system method that combines the Taylor rule and a standard exchange rate model to estimate half-lives. Further, we propose a median unbiased estimator for the system method based on the generalized method of moments with non-parametric grid bootstrap confidence intervals. Applying the method to real exchange rates of 18 developed countries against the US dollar, we find that most half-life estimates from the single equation method fall in the range of 3-5 years, with wide confidence intervals that extend to positive infinity. In contrast, the system method yields median-unbiased estimates that are typically shorter than 1 year, with much sharper 95% confidence intervals. Our Monte Carlo simulation results are consistent with an interpretation of these results that the true half-lives are short but long half-life estimates from single-equation methods are caused by the high degree of uncertainty of these methods. © 2014 John Wiley & Sons, Ltd.

This paper defines the concepts of indirect and direct risk premium effects and analyzes their properties in an exchange rate model. In the model, these effects are endogenously determined in a rational expectations equilibrium. For the effect of an interest rate shock, they have the opposite signs and the indirect risk premium effect can dominate the direct risk premium effect under reasonable parameters. This means that domestic short-term bonds and foreign bonds are complements in the model even though domestic long-term bonds and foreign bonds are substitutes. This model, focusing on the indirect risk premium effect and on the term structure of interest rates, can be combined with a small sample bias approach to explain stylized facts about the forward premium anomaly, which is found for short-term interest rates, but not for long-term interest rates. © 2013 Blackwell Publishing Ltd.

This article develops and studies a tough love model of intergenerational altruism. We model tough love by modifying the Barro-Becker standard altruism model in two ways. First, the child's discount factor is endogenously determined, so lower childhood consumption leads to a higher discount factor later in life. Second, the parent evaluates the child's lifetime utility with a constant high discount factor. Our model predicts that parental transfers will fall when the child's discount factor falls. This is in contrast with the standard altruism model, which predicts that parental transfers are independent of exogenous changes in the child's discount factor. © (2012) by the Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.

This paper analyzes an approach to correcting spurious regressions involving unit-root nonstationary variables by generalized least squares (GLS) using asymptotic theory. This analysis leads to a new robust estimator and a new test for dynamic regressions. The robust estimator is consistent for structural parameters not just when the regression error is stationary but also when it is unit-root nonstationary under certain conditions. We also develop a Hausman-type test for the null hypothesis of cointegration for dynamic ordinary least squares (OLS) estimation. We demonstrate our estimation and testing methods in three applications: (i) long-run money demand in the U.S., (ii) output convergence among industrial and developing countries, and (iii) purchasing power parity (PPP) for traded and non-traded goods. © 2007 Elsevier B.V. All rights reserved.

This paper develops a system instrumental variable method to estimate the speed of adjustment coefficient in the long-run equilibrium of structural error correction models for a class of linear rational expectations models. This method is applied to an exchange rate model with sticky prices, in which the speed of adjustment coefficient governs the half-life of the real exchange rate. Compared to single equation methods, the system method gives smaller half-life estimates with sharper standard errors. © 2007 The Ohio State University.

We estimate the long-run Japanese money demand function in a cointegration framework with two nonlinear functional forms that allow for the liquidity trap, and compare the results with the standard log-level functional form. In addition to the conventional linear cointegration techniques, we also use a recently developed procedure for nonlinear cointegration that allows the estimation of alternative functional forms under the same assumption regarding the trend properties of the nominal interest rate. The nonlinear functional forms outperform the log-level functional form based on out-of-sample prediction performance. Copyright 2006 by The Ohio State University.

We propose the parametric Dynamic Seemingly Unrelated Regression (DSUR) estimator for simultaneous estimation of multiple cointegrating regressions. DSUR is efficient when the equilibrium errors are correlated across equations and is applicable for panel cointegration estimation in environments where the cross section is small relative to the available time series. We study the asymptotic and small sample properties of the DSUR estimator for both heterogeneous and homogeneous cointegrating vectors. We then apply the method to analyse two long-standing problems in international economics. Our first application revisits the estimation of long-run correlations between national investment and national saving. Our second application revisits the question of whether the forward exchange rate is an unbiased predictor of the future spot rate. © 2005 The Review of Economic Studies Limited.

This article develops a method for testing the risk-sharing hypothesis (RSH) against various versions of the permanent income hypothesis (PIH) while allowing for heterogeneity in risk preferences across households. Using 1-year and longer differences in household total nondurable consumption data from Indian villages, we find evidence that favors the RSH over the PIH at the village level.

This paper investigates the effects of shocks to US monetary policy on the dollar-yen exchange rate, using structural Vector error correction model (VECM) methods with long-run restrictions. We compare our estimates of the impulse responses with those based on levels Vector autoregression (VAR) with standard recursive order restrictions. The empirical results based on the long-run restrictions are found to be more consistent with standard models of exchange rate determination than the results based on the recursive order restrictions. © 2003 Elsevier Inc. All rights reserved.

This paper proves a complete market aggregation result for a multiple good economy in which the consumers have time-additive, von Neumann-Morgenstern utility functions. This result applies to all concave intraperiod functions, and provides a contrast to many of the results in the microeconomics literature which depend on such stringent assumptions as linear Engel curves. © 2003 Elsevier Inc. All rights reserved.

Mexico adopted a floating exchange rate regime in December 1994. The Bank of Mexico's monetary policy gives attention to maintain 'orderly conditions in foreign exchange markets.' The Bank of Mexico relies primarily on the control of the overnight interest rate in conducting its monetary policy. The question arises whether this extremely short-term interest rate is the relevant instrument to achieve exchange rate objectives. Theory suggests that the relationship between the exchange rate and the term structure of interest rates can be complicated and counterintuitive when investors are risk averse. In this paper, we pursue an empirical investigation on the effect of the term structure of interest rates on the exchange rate for Mexico. This information could be useful to understand and manage the operation of the Mexican floating exchange rate regime. (C) 2000 Elsevier Science B.V. All rights reserved.

This paper re-examines whether the time series properties of aggregate consumption, real wages, and asset returns can be explained by a neoclassical model. Previous empirical rejections of the model have suggested that the optimal labour contract model might be appropriate for understanding the time series properties of the real wage rate and consumption. We show that an optimal contract model restricts the long-run relation of the real wage rate and consumption. We exploit this long-run restriction (cointegration restriction) for estimating and testing the model, using Ogaki and Parks (1989) cointegration approach. This long-run restriction involves a parameter that we call the long-run intertemporal elasticity of substitution (IES) for non-durable consumption but does not involve the IES for leisure. This allows us to estimate the long-run IES for non-durable consumption from a cointegrating regression. Tests for the null of cointegration do not reject our model. As a further analysis, our estimates of the long-run IES for non-durable consumption are used to estimate the discount factor and a coefficient of time-nonseparability using Hansens (1982) Generalized Method of Moments. We form a specification test for our model à la Hausman (1978) from these two steps. This specification test does not reject our model. © 1996 by John Wiley & Sons, Ltd.

The relationship behveen real interest rates saving and growth is a central issue in development economics. Using macroeconomic data for a cross-section of countries we estimate a model in which the intertemporal elasticity of substitution varies with the level of wealth. The estimated parameters are used to calculate in the context of a simple endogenous growth model the responsiveness of saving to real interest rate changes for countries at differing stages of development. The hypothesis that the saving rate and its sensitivity to the interest rate are a risins function of income finds strong empirical support. © 1996 International Monetary Fund.

This paper constructs and estimates a model of consumer preferences in which the intertemporal elasticity of substitution (IES) of consumption expenditure rises with the level of wealth. The purpose of this paper is to measure the effect that systematic variation in the IES of poor and rich consumers has on the IES of aggregate consumption expenditure. We find economically significant differences in the IES of poor and rich consumers in Indian panel data on the consumption of individual households. We also find economically significant differences in the IES measured in aggregate time series data for the U.S. and India.