从有效市场假说到分形市场假说

介绍了有效市场假说理论的形成与发展以及有效市场假说所引发的争论。阐述了分形市场假说的基本理念,并对我国证券市场(以上海证券市场为例)的分形结构进行了实证分析。结果表明:中国证券市场具有明显的分形特征和持续性,股票的收益率不符合随机游走过程。股票收益率序列不是独立的,具有约62周的长期记忆性。     

Variance bounds for estimators in autoregressive models with constraints

We consider nonlinear and heteroscedastic autoregressive models whose residuals are martingale increments with conditional distributions that fulfil certain constraints. We treat two classes of constraints: residuals depending on the past through some function of the past observations only, and residuals that are invariant under some finite group of transformations. We determine the efficient influence function for estimators of the autoregressive parameter in such models, calculate variance bounds, discuss information gains, and suggest how to construct efficient estimators. Without constraints, efficient estimators can be given by weighted least squares estimators. With the constraints considered here, efficient estimators are obtained differently, as one-step improvements of some initial estimator, similarly as in autoregressive models with independent increments.     

专家荐股信息的实证研究

对荐股信息发布后股票回报率的研究,显示分析师并没有预测股票未来走势的能力,依照他们的推荐来买卖股票不能提供超额的回报。荐股信息对投资人的投资决策有显著的影响。     

Root n consistent and optimal density estimators for moving average processes

Abstract.  The marginal density of a first order moving average process can be written as a convolution of two innovation densities. Saavedra & Cao [Can. J. Statist. (2000), 28, 799] propose to estimate the marginal density by plugging in kernel density estimators for the innovation densities, based on estimated innovations. They obtain that for an appropriate choice of bandwidth the variance of their estimator decreases at the rate 1/ n . Their estimator can be interpreted as a specific U -statistic. We suggest a slightly simplified U -statistic as estimator of the marginal density, prove that it is asymptotically normal at the same rate, and describe the asymptotic variance explicitly. We show that the estimator is asymptotically efficient if no structural assumptions are made on the innovation density. For innovation densities known to have mean zero or to be symmetric, we describe improvements of our estimator which are again asymptotically efficient.     

我国省区服务业综合竞争力的DEA组合评价

我国服务业发展的地区不平衡及服务业内部的结构性不平衡问题较为突出,本文运用超效率DEA的两阶段法对我国各省区第三产业、传统服务业和新兴服务业的发展状况进行了分析评价,并进一步分析指出影响服务业发展的深层次因素。     

多目标规划Hartley真有效解的自身对偶性

本文在Ｈａｒｔｌｅｙ真有效解的意义下讨论自身对偶性，得到了类似于［１］和［２］中的结果。     

行为金融学发展研究

20世纪 80年代以来 ,有效市场假说在理论和实践上受到了严峻的挑战 ,行为金融学逐渐兴起。文章在国内外研究的基础上阐述了行为金融学产生的历史背景、发展阶段 ,分析了行为金融学的理论基础 ,概括了行为金融学的主要模型并指出行为金融学未来的发展方向。     

封闭型基金折价之谜研究述评

封闭型基金折价是一个一直困扰人们的难解之谜,它违背了有效市场假说,是对现代金融理论的一种挑战。文章介绍了封闭型基金折价之谜,并结合现代金融理论、行为金融理论和一些最新研究成果综述了对封闭型基金折价之谜的种种解释,有助于进一步理解和研究这一现象。     

组合证券投资有效边界的进一步研究

研究了不允许卖空情况下有效证券组合的结构特征，证明了其有效边界由一系列开口向上的抛物线段光滑连接而成，给出了连续确定有效证券组合构成变动及相应的有效边界的方法，并将有关结果推广到考虑外汇套期保值的国际组合证券投资决策中。     

On estimation of the mean parameter of a truncated normal disiribution with known coefficient of variation

This paper eals with the proplem on estimating the mean paramerer of a truncated normal distribution with known coefficient of variation. In the previous treatment of this problem most authors have used the sample standared deviation for estimating this parameter. In the present paper we use Gini’s coefficient of mean difference g and obtain the minimum variance unbiased estimate of the mean based on a linear function of the sample mean and g, It is shown that this new estimate has desirable properties for small samples as well as for large samples. We also give a numerical example.