Further Evidence on Foreign Exchange Market Efficiency: An Application of Cointegration Tests

This study extends and expands the body of evidence related to foreign exchange market efficiency by employing the single-equation cointegration test proposed by Phillips and Ouliaris [19], and the Johansen [12] 1991 Full Information Maximum Likelihood procedure for a system of equations. Through the use of these updated techniques and a global data set, the authors are able to more carefully test for the presence of cointegrating relationships and examine the consistency of the results in three trading locations. The results are quite consistent across locations and are highly supportive of efficiency in the global foreign exchange market.     

Cointegration, Efficiency and Forecasting in the Currency Market

Existing literature on using the cointegration approach to examine the efficiency of the foreign exchange market gives mixed results. Arguments typically focus on econometric testing techniques, with fractional cointegration being the most current one. This paper tries to look at the issue from an economic perspective. It shows that the cointegrating relationship, whether cointegrated or fractionally cointegrated, is found mainly among the currencies of the European Monetary System which are set to fluctuate within a given range. Hence, there is no inconsistency with the notion of market efficiency. Yet, exploiting such a cointegrating relationship is helpful in currency forecasting. There is some evidence that restricting the forecasting model to consist of only cointegrated currencies improves forecasting efficiency.     

外汇市场的分形分析

首先分析了外汇市场的EMH，指出了其线性范式与现实市场状况并不相符，然后通过实证，指出了外汇汇率变化不服从正态分析，而是服从分形分布；最后运用R/S方法对外汇变化进行了分形分析，提出汇率变化遵循有偏的随机游走，呈现出状态持续性，对外汇市场风险的度量提出了一些新的看法，并提出了几点政策建议。     

Forecasting Emerging Market Exchange Rates from Foreign Equity Options

The use of derivatives to infer future exchange rates has long been a subject of interest in the international finance literature. With the recent currency crises in Mexico, Southeast Asia, and Brazil, work on exchange rate expectations in emerging markets is of particular interest. For some emerging markets, foreign equity options are the only liquid exchange‐traded derivatives with currency information embedded in their prices. Given that emerging markets sometimes undergo currency realignment with discrete jumps in their exchange rate, estimation of risk‐neutral probability density functions from foreign equity option data provides valuable evidence concerning market expectations. To illustrate the use of foreign equity options in estimating market beliefs, we consider Telmex options around the 1994 peso devaluation and find evidence that markets anticipated the change in the Mexican government's foreign exchange policy.     

Foreign Currency Derivatives versus Foreign Currency Debt and the Hedging Premium

This paper compares the effect on firm value of different foreign currency (FC) financial hedging strategies identified by type of exposure (short‐ or long‐term) and type of instrument (forwards, options, swaps and foreign currency debt). We find that hedging instruments depend on the type of exposure. Short‐term instruments such as FC forwards and/or options are used to hedge short‐term exposure generated from export activity while FC debt and FC swaps into foreign currency (but not into domestic currency) are used to hedge long‐term exposure arising from assets located in foreign locations. Our results relating to the value effects of foreign currency hedging indicate that foreign currency derivatives use increases firm value but there is no hedging premium associated with foreign currency debt hedging, except when combined with foreign currency derivatives. Taken individually, FC swaps generate more value than short‐term derivatives.     

新兴市场国家外汇储备适度规模研究

本文基于外汇储备的职能划分外汇储备的需求层次,建立了外汇储备适度规模测算模型,选取了中国、巴西、俄罗斯、印度、南非五个金砖国家作为新兴市场国家的典型代表,力图通过研究这五个金砖国家的外汇储备适度规模问题,从这一新角度界定新兴市场国家外汇储备适度规模区间,为新兴市场国家外汇储备管理提供有益的参考。实证研究中,通过测算金砖国家2000-2010年的外汇储备适度规模区间,我们发现以"金砖国家"中国、俄罗斯、巴西为代表的一些新兴市场国家的外汇储备逐渐偏离适度外汇规模上限;同时以南非为代表的一部分新兴市场国家,外汇储备水平一直处于不足的状态;而印度良好的外汇储备管理政策使得其外汇储备量一直保持在适度规模区间内。最后,针对各个新兴市场国家外汇储备处于的不同状态,我们提出了相应的政策建议。     

Learning, Asset-Pricing Tests, and Market Efficiency

This paper studies the asset-pricing implications of parameter uncertainty. We show that, when investors must learn about expected cash flows, empirical tests can find patterns in the data that differ from those perceived by rational investors. Returns might appear predictable to an econometrician, or appear to deviate from the Capital Asset Pricing Model, but investors can neither perceive nor exploit this predictability. Returns may also appear excessively volatile even though prices react efficiently to cash-flow news. We conclude that parameter uncertainty can be important for characterizing and testing market efficiency.     

金融市场有效性联立检验的再检验

在理性预期假定下,基于证券历史价格和收益信息,不能预测证券的未来价格,即市场是弱有效的。对市场有效性检验无效可能是关于基本价格或者正常收益均衡模型设定有误所导致,借助C-CAPM与行为金融模型可以对"市场无效性"进行解释。研究表明,市场有效性假说仅为一个理想范式,无论从有效性的联立检验角度,还是从非理性投资与金融市场关系的角度,都无法对现实的金融市场是否有效做出明确的判断。     

The Intertemporal Relationship Between the Currency Spot Market and the Currency Option Market

This study examines the lead/lag relationship between currency option and currency spot markets for the Deutsche mark and the Japanese yen. Using intraday currency option transactions data for the year 1989 and applying a European type currency option pricing model, pair data series of the implied and the observed exchange rates are compiled. Causality tests are then employed to test the causal relation between the observed and the implied exchange rate changes. The results indicate that the currency spot market leads the currency option market by about ninety minutes.     

Market Reform and Efficiency: The Case of KOSPI200 Options

The Korean government and exchange have identified a need to regulate excessive speculative trading and to protect domestic individual investors from foreign and professional traders. As such, they have proposed an options market reform that requires higher levels of margin accounts for options trading and that increases the basic options multipliers in the KOSPI200 options market. This study examines how this market reform affects the price disagreement and adjustment behaviors of the index options market. Our analyses indicate that the efficiency and information quality of out-of-the-money options trades have increased since the reform took effect.     

Expectations Hypothesis of the Term Structure of Implied Volatility: Evidence from Foreign Currency and Stock Index Options

Using a stochastic volatility option pricing model, we showthat the implied volatilities of at-the-money options are notnecessarily unbiased and that the fixed interval time-seriescan produce misleading results. Our results do not support theexpectations hypothesis: long-term volatilities rise relativeto short-term volatilities, but the increases are not matchedas predicted by the expectations hypothesis. In addition, anincrease in the current long-term volatility relative to thecurrent short-term volatility is followed by a subsequent decline.The results are similar for both foreign currency and the S&P500 stock index options.     

外汇期权信息含量与在岸离岸市场效率

央行在“8·11”汇改后放松了汇率中间价的管理,采用更为市场化的方式形成中间价,这种变化对于人民币汇率衍生品市场的影响尚属未知。为此,本文从人民币期权组合的Black-Scholes隐含波动率历史报价数据中提取出在岸、离岸市场人民币期权的无模型隐含波动率和风险中性偏度,在将样本划分为汇改前后三个不同的阶段的基础上,检验了期权隐含指标对未来汇率分布的预测能力。实证结果表明,在“8·11”汇改之后,随着人民币中间价形成机制变得更加市场化,期权价格中包含了越来越多关于未来汇率分布的信息,在岸和离岸期权市场的信息效率都有显著提高,意味着人民币中间价形成机制的市场化能显著提升我国金融市场效率。因此,在兼顾金融安全的角度上,稳步促进人民币中间价形成机制市场化进程将有利于我国金融市场效率的提高。     

Overreactions in the Options Market

This paper examines the “term structure” of options' implied volatilities, using data on S&P 100 index options. Because implied volatility is strongly mean reverting, the implied volatility on a longer maturity option should move by less than one percent in response to a one percent move in the implied volatility of a shorter maturity option. Empirically, this elasticity turns out to be larger than suggested by rational expectations theory—long-maturity options tend to “overreact” to changes in the implied volatility of short-maturity options.     

Pricing Efficiency in a Thin Market with Competitive Market Makers: Box Spread Strategies in the Hang Seng Index Options Market

Using a box spread arbitrage strategy, we examine the pricing efficiency of the emerging, thinly traded Hang Seng Index options market in Hong Kong, where market makers operate under a competitive open outcry system. In 20 months of tick‐by‐tick bid‐ask and transaction quotes we find very few arbitrage opportunities. Our examination of the reporting time of quotes shows that in effect, all the apparent mispricings are deceptive and could be explained by stale quotes. The absence of real arbitrage opportunities supports the pricing rationality hypothesis in the Hong Kong options market.     

构建本外币跨境资金监管机制

自2009年7月跨境贸易人民币结算试点以来,人民币跨境结算量呈爆发性增长。据中国人民银行数据公布,2012年累计办理跨境贸易人民币结算业务2.94万亿元,较上年增长41%,办理人民币跨境直接投资结算业务2840.2亿元,同比增长152.66%。据环球银行金融电信协会（SWIFT）数据显示,2012年12月份,人民币已成为全球第十三大支付货币,跨境人民币已经兼具了本位币和国际货币的双重职能。但由于跨境人民币与外汇资金在监管主体、管理方式等方面存在一些不同,增加了本外币联动监管难度。     

The Determinants of Foreign Currency Hedging: Does Foreign Currency Debt Induce a Bias?

In this paper we use UK data to present strong empirical evidence that explains the mixed results in previous studies with respect to the effect of financial distress on the demand for corporate hedging. We build on recent studies that have identified a strong link between foreign currency (FC) debt use and leverage. Given this relationship, we show that using leverage variables as proxies for financial distress and the failure to distinguish between FC debt users and non‐users causes misleading inference. More specifically, when we partition our sample of FC hedgers into firms that use and do not use foreign debt, we show that leverage variables are significantly related to the FC hedging decision for firms that use FC debt either in isolation or in combination with FC derivatives but not for firms that only use FC derivatives. This suggests that FC debt users are influencing these results. However, we also find that other financial distress cost proxies with no obvious link to FC debt use are significant determinants in the corporate demand for FC hedging, including derivatives use.     

论外币会计报表折算

随着国际贸易、跨国投资和跨国子公司的发展，由此带来的外币业务和外币会计报表的折算问题将越来越重要。而现在外币折算方法，未能从理论上作出全面、系统、合理的解释，违反了历史成本原则或谨慎性原则或两者。     

The Trading Volume of Currency Options and the Spot Exchange Rate

This paper estimates the interrelation between the spot exchange rate of the Israeli currency, the new Israeli shekel, to the U.S. dollar, and the trading volumes of put and call options on the U.S. dollar in the Tel Aviv Stock Exchange. An increase in the trading volume of calls is positively correlated with an increase in the spot exchange rate of the dollar on the same day and the following day, but with a lower coefficient. Similarly, an increase in the trading volume of puts is related to a decrease in the spot price of the dollar on the same day of trade, with a smaller effect on the following day.