Components of the Bid-Ask Spread and the Statistical Properties of Transaction Prices

The bid-ask spread can be decomposed into two parts: one part due to asymmetric information and the other part due to other factors such as monopoly power. The part due to asymmetric information attenuates statistical biases in mean return, variance, and serial covariance. Thus, using spread data to adjust for biases in return moments requires knowing not only the spread but the composition of the spread. Furthermore, any spread-estimation procedure using transaction prices must estimate two spread components. On the other hand, the appropriateness of some previously suggested statistical corrections is independent of the spread composition.     

The Impact of Bid-Ask Prices on Market Anomalies

A substantial body of literature on security market anomalies has evolved since the articulation of the efficient markets hypothesis. These anomalies include the size, January, and weekend effects. The evidence of such anomalies has been based upon returns computed from closing prices. Although readily available, analysis of closing prices may not reflect returns obtainable by public traders utilizing market orders to execute trades. We have demonstrated elsewhere that returns computed from closing prices are biased upward compared with returns that would have resulted from using market orders. This study reexamines the evidence on two market anomalies using returns generated in a manner more consistent with the actual returns available to actual market participants.     

Intraday Variation in the Bid-Ask Spread: Evidence after the Market Reform

In this article we show that intraday variation in spreads for Nasdaq‐listed stocks has converged to intraday variation in spreads for NYSE‐listed stocks after the implementation of the new order‐handling rules. We attribute this convergence to the Limit Order Display Rule, which requires that limit orders be displayed in Nasdaq best bid and offer when they are better than quotes posted by market makers. Our findings suggest that the different patterns of intraday spreads between NYSE and Nasdaq stocks reported in prior studies can largely be attributed to the different treatment of limit orders between the NYSE and Nasdaq before the market reform.     

上海银行间同业拆借市场买卖价差研究

本文考察了上海银行间同业拆借市场做市商买卖价差的特征,并研究了该价差的影响因素。实证结果表明,上海银行间同业拆借市场做市商的买卖价差具有显著的聚集效应,不同类型银行的买卖价差水平在不同拆借品种上是不一致的：隔夜拆借的买卖价差具有显著的周内效应,呈现倒“V”特征,在周三的买卖价差是最高的：买卖价差假日交易的波动更小;在正式运行阶段,买卖价差的波动率均有很大提高,对于交易活跃的拆借品种来说,其买卖价差水平均有所下降。本文采用了AR（1）-GJR（1,1）对Shibor的条件异方差进行建模。OLS回归模型表明上海银行间同业拆借市场的买卖价差并不受市场利率和市场波动的影响,与成熟市场买卖报价的影响模式存在显著差异。这说明上海银行间同业拆借市场做市商的定价水平有待提高。     

Dealer Bid-Ask Quotes and Transaction Prices: An Empirical Study of Some AMEX Options

This paper, utilizing dealer's “trading book” information, presents some empirical evidence supporting the validity of a dealer pricing model. It shows that much of the transaction prices variation may be explained by the specialist's optimal determination of his bid and ask quotes. Furthermore, it demonstrates that the dealer's bid-ask spread is an important explanatory variable in the observed transaction return. Finally, it indicates that the dealer's inventory level may affect his quotes and thus the transaction prices and order arrivals. The paper provides insights into the relationship between transaction prices and equilibrium prices, which will permit more extensive use of transaction data in empirical investigations. It also provides a better understanding of optimal dealer pricing strategies, suggesting that the proposed empirical model may be used to evaluate a dealer's trading performance.     

Trading Mechanisms and the Components of the Bid-Ask Spread

We compare the relative magnitudes of the components of the bid-ask spread for New York Stock Exchange (NYSE)/American Stock Exchange (AMEX) stocks to those of National Association of Securities Dealers Automated Quotations (NASDAQ)/National Market System (NMS) stocks. We find that the order-processing cost component is smaller, and the adverse selection component is greater on the NYSE/AMEX trading systems than on the NASDAQ/NMS system. The inventory holding component is also greater for exchange-traded stocks than for NASDAQ/NMS stocks, but this may be attributable to differences in the characteristics of the firms whose stocks trade on the respective systems.     

Decomposing the Bid-Ask Spread in a Segmented Equity Market: Analyzing Chinese A Shares Versus B Shares

Because of a regulatory policy change in February 2001, the segmentation of the Chinese stock market significantly decreased. Using this event, we show that the Chinese A-share market is more informationally efficient than the B-share market, both before and after the opening of the B-share market. Furthermore, after the event, both the adverse selection and the order-processing component of B shares decreased, as a result of a larger investor base and possibly a lower proportion of informed investors. This study thus sheds new light on the market segmentation and its effect on transaction costs.     

The Post-Reform Bid-Ask Spread Disparity between Nasdaq and the NYSE

We report further evidence of the difference in execution costs between Nasdaq and the NYSE before and after the 1997 market reforms. We find that informed trading costs are consistently higher on Nasdaq both before and after the reforms. In the pre‐reform period the Nasdaq‐NYSE disparity in bid‐ask spreads cannot be completely attributed to the difference in informed trading costs. However, in the post‐reform period the spread difference between these two markets becomes insignificant with the effect of informed trading costs controlled. Our findings are consistent with the contention that the reforms have largely reduced noninformation trading costs and dealers' rents.     

Detecting Abnormal Bid-Ask Spread: A Comparison of Event Study Methods

This study examines empirical issues associated with the use of bid-ask spreads in event studies. The simulation results indicate that the distribution of average standardized abnormal spread shows little deviation from normality. Simulation results also indicate that the widely used percent spread metric results in test statistics with low power. In contrast, use of a standardized raw spread metric and a simple mean-adjusted expectation model results in well specified and reasonably powerful Patell and Brown-Warner type test statistics. As the abnormal spread series is characterized by high first order serial correlation, it is important to adjust for this serial correlation when using multi-day event windows.     

Hedging Strategies of Financial Intermediaries: Pricing Options with a Bid-Ask Spread

This paper uses a model similar to the Boyle-Vorst and Ritchken-Kuo arbitrage-free models for the valuation of options with transactions costs to determine the maximum price to be charged by the financial intermediary writing an option in a non-auction market. Earlier models are extended by recognizing that, in the presence of transactions costs, the price-taking intermediary devising a hedging portfolio faces a tradeoff: to choose a short trading interval with small hedging errors and high transactions costs, or a long trading interval with large hedging errors and low transactions costs. The model presented here also recognizes that when transactions costs induce less frequent portfolio adjustments, investors are faced with a multinomial distribution of asset returns rather than a binomial one. The price upper bound is determined by selecting the trading frequency that will equalize the marginal gain from decreasing hedging errors and the marginal cost of transactions.     

中国股市开、收盘波动性的比较研究

利用EGARCH模型,对2000年1月至2007年4月间沪深两市具有代表性的股票及指数的开收盘收益率的波动性进行实证分析,结果表明收益率序列有明显的ARCH效应,其波动性具有显著的非对称性的冲击的持续性;在样本期内,上交所的个股和指数未能观察到开盘波动性高于收盘波动性的现象,而深交所个股在2006年7月实施收盘集合竞价机制之后比较明显地观察到开盘波动性高于收盘波动性的现象。     

Information Asymmetry and the Dealer's Bid-Ask Spread: A Case Study of Earnings and Dividend Announcements

Recent theoretical work on the bid-ask spread asserts that the dealer should widen the bid-ask spread when he or she suspects that the information advantage possessed by informed traders has increased. Thus, the dealer's spread can be employed to test for an increase in information asymmetry prior to an anticipated information event. In this paper, the method is applied to earnings and dividend announcements, which have been documented to be information events. The authors study three groups of announcements: (a) joint announcements—i.e., earnings and dividend announcements that are made on the same day, (b) initial (first) announcements—earnings or dividend announcements that were not preceded by another announcement in the prior thirty days, and (c) following (second) announcements—those announcements that follow the first announcement by at least ten days but by no more than thirty days. The authors find a strong increase in information asymmetry only before the second announcements and virtually no increase before the joint and first announcements. This is consistent with the hypothesis that there is, on average, normal information asymmetry before announcements, but that the dealer will suspect a nonroutine announcement (with an attendant increase in information asymmetry) when the second announcement is separated from the first by more than ten days. Other possible explanations for the results are discussed, and suggestions for future research are outlined.     

上海黄金市场期现价格的实证分析

本文以上海黄金市场的期货和现货价格为样本,建立VAR和VECM模型对上海黄金市场进行实证研究。研究结果表明,上海黄金市场的期现货价格之间存在协整关系;期货价格是市场价格的先行指标,是引导现货价格变化的Granger原因;上海黄金期货市场具有价格发现功能,并且具有较强的调整作用。     

Commodity Prices and Stock Market Behavior in South American Countries in the Short Run

Using Geweke feedback measures, we present empirical evidence that largely supports the hypothesis that the stock markets of South American countries are highly affected by changes in commodity prices after controlling for changes in exchange rates, interest rates, and North American stock market changes. In total, six different Goldman Sachs commodity price indexes are tested against the unexplained variation in stock market returns for Argentina, Brazil, Chile, Colombia, Peru, and Venezuela, covering the period 1995-2007. The Argentinian, Brazilian, and Peruvian stock markets are significantly affected by changes in commodity prices the same day. Venezuela's stock market, however, does not react to changes in commodity prices, even including energy prices. Stock market returns for Chile show a contemporaneous relation with energy and metals prices, whereas Colombia's equity market is affected by price changes for agricultural and industrial metals. In all cases, we find a contemporaneous relation and no indication of a lead or lag relationship.     

中国证券市场羊群行为实证研究

引言 羊群行为(Herd Bchavior)是指投资者在交易过程中观察并模仿他人的交易行为,从而导致某段时期内买卖相似的股票.20世纪90年代以来,随着金融学术界将研究重点转移到非基础经济因素对股价的影响上,投资者行为、特别是羊群行为对股价的影响得到了广泛关注和研究.     

Consumer Confidence and Asset Prices: Some Empirical Evidence

We explore the time-series relationship between investor sentimentand the small-stock premium using consumer confidence as a measureof investor optimism. We estimate the components of consumerconfidence related to economic fundamentals and investor sentiment.After controlling for the time variation of beta, we study thetime-series variation of the pricing error with sentiment. Overthe last 25 years, investor sentiment measured using consumerconfidence forecasts the returns of small stocks and stockswith low institutional ownership in a manner consistent withthe predictions of models based on noise-trader sentiment. Sentimentdoes not appear to forecast time-series variation in the valueand momentum premiums. (JEL G10, G12, G14)