Size,time-varying beta,and conditional heteroscedasticity in UK stock returns

The purpose of this study is to examine the relationship between firm size and time-varying betas of UK stocks. We extend the Schwert and Seguin (1990)(Journal of Finance 45, 1120–1155) methodology by explicitly modeling conditional heteroscedasticity in the market model residual returns. Our results show that the time-varying coefficient is not statistically significant for both small and large firm stock indexes. We also find that accounting for GARCH effects in the Schwert-Seguin market model yields beta estimates that are markedly differently from those when conditional heteroscedasticity is ignored. Event studies that ignore conditional heteroscedasticity may bias the abnormal returns of small and large firms, thereby leading to a different conclusion regarding the significance of an information event.     

VaR及对证券投资基金的VaR测算

本在对VaR方法的分析的基础上，选择了GAROH模型度量证券投资基金的风险，并计算了样本期间22只基金的VaR值。在此基础上给出了各基金对应的RAROC值，并对结果进行了分析。     

基于遗传算法的中国股市波动性研究

本文介绍了金融市场波动性过程的长期记忆性特征的分整自回归条件异方差模型——FIGARCH（p,d,q）,并介绍了一种建立FIGARCH模型的新方法——遗传算法。对上证综合指数进行实证分析,对其收益率建立自回归模型（AR模型）,由Eviews软件可知模型的残差项具有明显的异方差效应,应用遗传算法的基本步骤进行C语言编程,由此求解FIGARCH模型的各项参数值,从而建立FIGARCH模型,实证结果表明中国股市波动性过程具有明显的长记忆性。     

Macroeconomic uncertainty and performance in the European Union

We use a very general bivariate GARCH-M model and monthly data on EU countries covering the 1962–2003 period to test for the impact of real (output growth) and nominal (inflation) macroeconomic uncertainty on inflation and output growth. Our evidence supports a number of important conclusions. First, in the majority of countries uncertainty regarding the output growth rate is related to the average growth rate and the effect in several countries is negative. Second, in half of the cases there is no significant relationship between inflation uncertainty and output growth performance. Third, inflation and output uncertainty have a mixed effect on inflation. Nevertheless, considerable evidence for the Cukierman–Meltzer hypothesis is obtained. Our conclusions are based on adopting both a structural and a reduced-form bivariate GARCH model. Finally, we also find statistically significant evidence of regime switching for both inflation and output growth volatility throughout the sample.     

ARCH and GARCH models vs. martingale volatility of finance market returns

ARCH and GARCH models assume either i.i.d. or ‘white noise’ as is usual in regression analysis, while also assuming memory in a conditional mean square fluctuation with stationary increments. We will show that ARCH/GARCH is inconsistent with uncorrelated increments, violating the i.i.d. and ‘white’ assumptions, and violating finance data and the efficient market hypothesis as well.     

Hedging Multiple Price Uncertainty in International Grain Trade

Commodity and freight futures contracts are analyzed for their effectiveness in reducing uncertainty for international traders. A theoretical model is developed for a trader exposed to several types of risk. OLS hedge ratio estimation is compared to the SUR and the multivariate GARCH methodologies. Explicit modeling of the time-variation in hedge ratios via the multivariate GARCH methodology, using all derivatives, and taking into account dependencies between prices, results in reductions in risk, even after accounting for transaction costs. Results confirm that while the commodity futures contracts are important for hedging risk, freight futures are a useful mechanism for reducing risk.     

沪深A、B股市场分割的实证研究——基于GARCH模型的收益率波动引导关系

运用计量经济学中GARCH模型和Granger因果性检验。分阶段实证检验了B股市场自对内开放以及汇率制度改革以来,沪深两市A、B指收益率波动的引导关系。得到的结论主要有：B股市场对内开放以来,沪深两市收益率波动的引导关系以及A、B指收益率波动的引导关系有所增强;特别是汇率制度改革以来,A、B股市场收益率波动的引导关系表现得更加显著。     

商品市场的金融化对价格波动性的影响研究——以纽约商品交易所（NYMEX）WTI原油为例

本文致力于研究商品市场的金融化如何影响价格的波动性,特别是相对于对冲交易,投机交易将如何影响价格的波动性。在本文的实证应用方面,我们考虑的变量是原油期货价格,在这里我们使用纽约商品交易所（NYMEX）WTI原油相关的数据,非商业参与者的净价差,非商业参与者的净头寸,非商业参与者的头寸总额,非商业参与者的头寸和头寸总额的比率,和非商业参与者的头寸和期货市场交易量的比率。实证研究表明,非商业参与者的投机活动将会增加石油价格的波动性。或者把它放人一个更广泛的概念,石油的金融化使得石油更像是一种投资工具而不是一种商品,并增加了其价格的波动性。其次,经过一段频繁交易期之后,市场对价格趋势将会得到一些共同的看法,价格将会进人一个更加稳定的通道。当然这点可能由于数据问题需要进一步论证。     

商业银行现金持有量与宏观经济不确定性关系研究——基于面板数据的实证检验

本文研究了宏观经济不确定性对中国商业银行现金持有水平的影响。论文首先构建了一个GARCH模型得到代理变量来度量宏观经济不确定性,然后利用中国银行业2000～2009年的面板数据,实证检验了宏观经济不确定性对中国银行业现金持有水平的影响情况。实证结果表明:宏观经济不确定性对银行现金持有水平影响显著,当宏观经济不确定性增加、经济形势前景不明时,商业银行现金持有水平显著降低。     

Trading volume and returns relationship in SET50 index futures market

This study investigates the relationship between trading volume and returns in SET50 index Futures market in the period from April 2006 to December 2008 using 653 observations. From previous studies, we include three methodologies namely the GARCH model, the Generalized Method of Moments （GMM） to estimate systems of equations and the Granger causality test to investigate the relationship more thoroughly. In addition, we introduce the lagged volume as a new explanatory variable in the GARCH model. Overall, the results show the significant contemporaneous and dynamic relationships between trading volume and returns volatility which support the sequential information arrival hypothesis and imply some degree of market inefficiency. The results from this study also show that past information of trading volume can be used to improve the prediction of price volatility. Therefore, regulators and traders could include past information of trading volume of SET50 index futures in tracking and monitoring the market volatility level and the investment risk in order to make a timely decision.