股指期货的套期保值问题

中国金融市场即将推出股票指数期货。本文吸收和借鉴了国外的研究成果,对股指期货的套期保值问题进行了系统研究,采用方差法和β系数法对风险最小化的套期保值比率进行了充分论证,并结合案例进行了模拟计算。本文根据资本资产定价模型,建立了一元线性回归方程,对流行的β系数法进行了检验和重要修正,对套期保值实践具有重要的指导意义。     

PICKING WINNERS? A SURVEY OF THE MEAN REVERSION AND OVERREACTION OF STOCK PRICES LITERATURE

Abstract. This paper surveys, and suggests a possible synthesis of, two growing literatures concerning stock market anomalies. The first concentrates on identifying contrarian trading rules, capable of generating profits, when securities are segregated on the basis of past earnings, or share price performance. The other simply examines the time-series properties of security prices to find evidence of low-frequency negative autocorrelation, or 'meanreversion'. We seek to articulate the points of interdependence between the two strands of research and the problems of joint hypothesis testing implied by the close relation between 'Overreaction'and 'mean-reversion'tests.     

Alternative measures of homeownership gaps across segregated neighborhoods

The dramatic rise in the U.S. homeownership rate from 64% in 1996 to almost 70% in 2005 has prompted increased attention to the relation between homeownership and demographic characteristics of households. The recent rise and sharp decline of subprime lending will likely spur further interest in homeownership gaps. Statistical analysis of these differences or “gaps” in homeownership between white and minority households has evolved into a highly stylized comparison of differences in homeownership at the mean or the conditional mean. This study implements a quantile decomposition technique that identifies the unexplained portion of the gap not only at the mean, but at every percentile of the homeownership distribution. Results suggest that differences in homeownership gaps at the mean reflect a combination of small differences at the upper end and much larger gaps at the lowest end of the distribution of homeowners. This study also adds credit history to the factors that are used to explain homeownership gaps.     

Herding behavior,market sentiment and volatility: Will the bubble resume?

This paper aims to investigate herding behavior and its impact on volatility under uncertainty. We apply a cross-sectional absolute deviation approach as well as Quantile Regression methods to capture the herding behavior in daily and monthly frequencies in US markets over several time-periods including the global financial crisis. In a novel attempt we modify the empirical CSAD herding modeling by introducing implied volatility as a measure of agent risk expectations. Our findings indicate that herding tends to be intense under extreme market conditions, as depicted in the upper high quantile range of the conditional distribution of returns. During crisis periods herding is observed at the beginning of the crisis and becomes insignificant towards the end. The US market herding behavior exhibits time-varying dynamic trading patterns that can be attributed e.g., to overconfidence or excessive “flight to quality” features, mostly observed in the aftermath of the global financial crisis. Moreover, implied volatility reveals asymmetric patterns and plays a key role in enforcing irrational behavior.     

The gender pay gap in the transition from communism: some empirical evidence

This short paper investigates the gender pay gap in a number of former communist countries of eastern Europe and the Soviet Union. The main findings are that, in general, the gender pay gap has not exhibited an upward tendency over the transitional period to which available data relate. Most of the gender pay gap is ascribed to the ‘unexplained’ component using conventional decompositions and this may partly be attributable to the proxy measure for labour force experience used in this study. Quantile regression analysis indicates that in all but one country, the ceteris paribus gender pay gap rises as we move up the wage distribution.     

Classroom peer effects and academic achievement: Quasi-randomization evidence from South Korea

Endogenous formation of peer groups often plagues studies on peer effects. Exploiting quasi-random assignment of peers to individual students that takes place in middle schools of South Korea, we examine the existence and detailed structure of academic interactions among classroom peers. We find that mean achievement of one's peers is positively correlated with a student's performance (standardized mathematics test score). Employing IV methods, we show that such a relationship is causal: the improvement in peer quality enhances a student's performance. Quantile regressions reveal that weak students interact more closely with other weak students than with strong students; hence their learning can be delayed by the presence of worst-performing peers. In contrast, strong students are found to interact more closely with other strong students; hence their learning can be improved by the presence of best-performing peers. We also examine the implications of these findings for two class formation methods: ability grouping and mixing.     

Time–frequency quantile dependence between Bitcoin and global equity markets

In this paper, we examine return dependence between Bitcoin and stock market returns using a novel quantile cross-spectral dependence approach. The results suggest a right-tail (high return) dependence between Bitcoin and the stock markets in the long term and that said dependence decreases significantly from yearly to monthly investment horizons. Furthermore, right-tail dependence between Bitcoin and the US stock market is the strongest compared with other stock markets. We also extract information on the time-varying and time–frequency structure of co-movements between Bitcoin and the stock markets using wavelet-coherence analysis, the results of which suggest that the co-movement between Bitcoin and the US stock market is positive, whereas, for other stock markets, it is negative at certain frequencies and time periods. Overall, the findings highlight additional risk-management capabilities of Bitcoin according to different stock markets.     

沪深300股指期货动态套期保值比率模型估计及比较——基于修正的ECM-BGARCH(1,1)模型的实证研究

本文以沪深300股指期货的真实交易数据及沪深300指数为研究对象,在最小方差套期保值的基础上,建立了ECM-BGARCH(1,1)的沪深300股指期货对沪深300指数的动态套期保值模型。其具体特色是:与利用沪深300股指期货仿真交易数据相比,通过利用沪深300股指期货的真实数据得到的最优套期保值比率更具真实性;通过建立具有时变特征、含有自相关和条件异方差的动态BGARCH(1,1)模型,不但考虑了实证所用数据的实际特点,而且保证了套期保值比率预测的准确性;实证研究结果表明,该模型优于现有的套期保值模型。