Deviations from Purchasing Power Parity in the Long Run

This paper demonstrates that deviations from purchasing power parity reveal a remarkable and possibly startling consistency with martingale behavior during both fixed and flexible rate periods, for a wide variety of countries, and in both monthly and annual data. Since this pattern appears to be much more general than one would expect on the basis of models founded on international commodity arbitrage, the paper proposes an alternative explanation which instead relies on financial arbitrage in bonds as the underlying mechanism.     

Deviations from Purchasing Power Parity

This study uses univariate and multivariate unit root tests to analyze the random walk behavior of real exchange rates for the period 1979–1989. The univariate test fails to reject the random walk model, but the multivariate test indicates that part of the real exchange rates is predictable, a result supporting purchasing power parity. Further analysis of the random walk component in real exchange rates shows that it is quite persistent: for all currencies it takes about five to eight years for this shock to diminish to half its size.     

购买力平价理论的实证检验法综述

本文介绍了自 2 0世纪 70年代以来开放经济理论的基石———购买力平价及实际汇率的相关实证检验方法。以发达国家双边汇率作为样本数据进行检验 ,发现在样本期间足够长、样本数量足够多的情况下 ,PPP假设成立。此外 ,由于实际汇率对PPP的均值复归呈现出显著的非线性特征 ,今后的研究方向应当是建立非线性汇率动态模型。     

关于购买力平价学说的研究综述

购买力平价学说是国际宏观经济学的一块重要基石.但其自产生之日起就面临着很多争论,这些争论主要包括汇率对购买力平价的短期偏离、购买力平价之谜与购买力平价的长期背离等方面.其中,对汇率的短期剧烈波动的解释、非线性的汇率变动与均值-回归行为、哈罗德-巴拉萨-萨缪尔森效应的存在性等都成为人们近年来研究的热点.     

购买力平价理论与中美汇率估值

购买力平价理论是现代汇率决定理论的基石之一,本文首先直观简要地分析了近三十多年中美两国通货膨胀率和汇率变化趋势,然后采用ADF和协整的方法对购买力平价的三变量模型进行了检验,最后在此基础上,利用相对购买力平价理论模型估值目前人民币对美元均衡汇率。     

购买力平价与人民币均衡汇率

购买力平价是衡量均衡汇率的最为重要的方法之一,依此方法对人民币低估程度的估计也曾经是最为严重的。本文就如何适当运用购买力平价来度量均衡汇率的问题做了系统性的文献回顾和评论。结合近期的相关研究,我们指出了在一些有关于人民币均衡汇率的讨论中所存在的需要商榷乃至于错误的地方。本文认为:相对于基本均衡汇率等方法,扩展型的购买力平价方法更适合于度量人民币均衡汇率水平;世界银行2005年购买力平价数据显著降低了关于人民币低估程度的估计,根本性改变了人民币汇率问题争议的形势,而有关世界银行数据本身被低估的观点未必成立;最后,当前人民币汇率并不存在严重的低估。     

Covered Purchasing Power Parity, Ex-ante PPP and Risk Aversion

The standard expectations augmented theory of ex-ante Purchasing Power Parity which was first developed by Roll assumes that agents are risk neutral. A Covered Purchasing Power Condition is developed which holds for the general case of risk aversion. A risk augmented form of ex-ante PPP is then derived using a consumption-based asset pricing framework. This is tested for the post-Bretton woods period for the group of seven main industrial countries. The results suggest that risk aversion has a part to play in explaining deviations from PPP.     

Natural Exchange Rate and Its Implications for the Purchasing Power Parity Puzzle

The notion of purchasing power parity has been an important building block in the theory of nominal and real exchange rates and for many theoretic models in international economics, leading to the purchasing power parity puzzle. The central issue of the puzzle is how to reconcile volatile short-term movements of real exchange rates (defined as nominal exchange rates adjusted for differences in national price levels) with very slow convergence to the parity condition. The main emphasis of this article is to show that the slow adjustment of the natural exchange rate is responsible for the well-known slow convergence of the real exchange rate to the long-run parity condition. The novel element of this article is to identify the relative importance between the financial channel and output gap channel of the purchasing power parity puzzle. The empirical findings of this article suggest that the financial channel is a dominant factor to explain persistent deviations of the real exchange rate from its long-run level.     

External Shocks, Purchasing Power Parity, and the Equilibrium Real Exchange Rate

Two approaches are commonly used to determine the equilibriumreal exchange rate in a country after external shocks: purchasingpower parity (PPP) calculations and the Salter-Swan, tradables-nontradablesmodel. There are theoretical and empirical problems with bothapproaches, and tensions between them. In this article we resolvethese theoretical and empirical difficulties by presenting amodel which is a generalization of the Salter-Swan model andwhich incorporates imperfect substitutes for both imports andexports. Within the framework of this model, the definitionof the real exchange rate is consistent both with that of thePPP approach and with that of the Salter-Swan model (suitablyextended). Our model, however, is capable of capturing a richerset of phenomena, including terms of trade shocks and changesin foreign capital inflows. It also provides a practical wayto estimate changes in the equilibrium real exchange rate, requiringlittle more information than is required to do PPP calculations.The results are consistent with those of multisector computablegeneral equilibrium models, which generalize the trade specificationof the small model.     

Migrants' Savings, Purchasing Power Parity, and the Optimal Duration of Migration

If some of the returns to migration accrue from returnmigration, the optimal duration of migration may be shorter thanthe feasible duration of migration. We develop a model that providesand highlights conditions under which return migration takesplace even though a reversal of the inter-country wage differentialdoes not occur. In particular, we consider the higher purchasingpower of savings (generated from work abroad) at home than abroadas a motive for return migration. Inter alia, our model producesa negative relationship between the optimal duration of migrationand the purchasing power differential and in some (but not all)cases, a negative relationship between the optimal duration ofmigration and the wage abroad. In addition, and contrary to ourprior anticipation, our utility maximization analysis suggeststhat East-West migration will tend to be temporary while inter-EuropeanCommunity (or intra-West European) migration will likely be permanent.     

对实际汇率偏离购买力平价的博弈论解释

对实际汇率的研究一直沿着购买力平价以及对购买力平价的偏离展开.本文把贝特兰德的双头垄断博弈模型扩展到两国,从两国生产差异产品出发,建立实际汇率决定基本模型.根据模型分析,我们得到结论:在其他条件相同的情况下,本国产品对外国产品的替代性增强、本国产品的市场需求增加、本国产品的边际生产成本上升或本国提高进口关税,本国实际汇率将升值;提高本国非贸易品生产部门的要素生产率,本国实际汇率将会贬值.     

Purchasing Power Parity and Efficiency of Black Market Exchange Rate in African Countries

This paper investigates the long-run dynamics of black and official exchange rates for ten African countries. Our major findings are, first, that parity holds more favorably when the black market rate is used to validate the purchasing power parity hypothesis. The evidence supports the notion that the speed of adjustment is much faster in the black market than in the official market. Second, the two rates are connected in the long run, with the official rate adjusting toward the black market rate for the majority of cases. Finally, we find the long-run informationally efficient hypothesis is supported in the majority of African countries.     

购买力平价变动影响因素研究:国际视角

购买力平价不仅在国际经济规模和结构比较中备受推崇,而且在社会经济管理中得到日益广泛的运用。本文选取77个经济体2001-2013年间的样本数据,考察各经济体不同年份购买力平价的变动特征及主要影响因素。统计分析表明,高收入经济体货币购买力平价年均变化相对较小,低收入特别是下中等收入经济体货币购买力平价年均变化相对较大。随着收入水平上升,购买力平价变动幅度呈先升后降特征。研究发现,PPP变动可由人均收入、名义汇率、货币供应、城镇化、贸易依存度和就业水平等因素解释。一般地,经济增长和货币供应增加将带动PPP上升,汇率升值和贸易依存度上升则往往伴随PPP下降。此外,PPP与城镇化水平变动方向一致,与就业水平变动方向相反。     

The Exchange Rate in the Presence of Transaction Costs: Implications for Tests of Purchasing Power Parity

With transaction costs for trading goods, the nominal exchange rate moves within a band around the nominal purchasing power parity (PPP) value. We model the behavior of the band and of the exchange rate within the band. The model explains why there are below-unity slope coefficients in regression tests of PPP, and why these increase toward unity under hyperinflation or with low-frequency data. Our results are independent of the presence of nontraded goods in the economy.     

Expectations of Exchange Rates and Differential Inflation Rates: Further Evidence on Purchasing Power Parity in Efficient Markets

The paper tests the null hypothesis of ex ante purchasing power parity. The empirical evidence obtained is inconsistent with the null for major industrialized countries over the current floating exchange rate regime. Expected nominal exchange rate changes appear to deviate systematically from expected inflation rate differentials over the same holding period even though real exchange rate changes appear to be serially uncorrelated. This supports the presence of time-varying risk premia in foreign exchange markets and real determinants of exchange rate movements as suggested by equilibrium theories of international asset markets.     

IPO Underpricing over the Very Long Run

A central measure of the efficiency of the Initial Public Offering (IPO) market is the extent to which issues are underpriced. We present new and comprehensive evidence covering British IPOs since World War I. During the period from 1917 to 1945, public offers were underpriced by an average of only 3.80%, as compared to 9.15% in the period from 1946 to 1986, and even more after the U.K. stock market was deregulated in 1986. The post-WWII rise in underpricing cannot be attributed to changes in firm composition, and occurred in spite of improvements in regulation, disclosure, and the prestige of IPO underwriters.     

购买力平价、人民币价值之谜与“双效应-三阶段曲线”假说

以"购买力平价"为代表的传统国际金融理论认为货币的对内价值与对外价值应该一致,然而近年来,人民币凸显了以"对内贬值与对外升值并存"为特点的"价值之谜"。本文从购买力平价出发提出"人民币价值之谜"问题、在对"谜"的成因进行简单分析的基础上,讨论购买力平价的适用性问题,并进一步提出以决定通胀与升值关系的"双效应-三阶段曲线"假说来解释"谜"的现象。     

Investing for the Long Run when Returns Are Predictable

We examine how the evidence of predictability in asset returns affects optimal portfolio choice for investors with long horizons. Particular attention is paid to estimation risk, or uncertainty about the true values of model parameters. We find that even after incorporating parameter uncertainty, there is enough predictability in returns to make investors allocate substantially more to stocks, the longer their horizon. Moreover, the weak statistical significance of the evidence for predictability makes it important to take estimation risk into account; a long-horizon investor who ignores it may overallocate to stocks by a sizeable amount.     

KLSE Long Run Overreaction and the Chinese New-Year Effect

This study investigates long run overreaction and seasonal effects for Malaysian stocks quoted on the Kuala Lumpur Stock Exchange (KLSE), for the period 1986–1996. Stocks exhibiting extreme returns relative to the market over a three year period experience a reversal of fortunes during the following three years. There is also evidence that employing a contrarian trading strategy may yield excess returns. Of particular interest is the apparent existence of a Chinese New Year effect in both the level of market returns, and the overreaction profile for KLSE stocks. These seasonalities mirror the January-effect observed in US markets.