中国股票市场贝塔系数稳定性研究

贝塔系数是用于衡量证券市场系统风险的一个重要概念,通过对贝塔系数的估计,投资者可以预测证券未来的市场风险。但是,贝塔系数要用过去的数据来估计,所以,除非贝塔系数具有相对的稳定性。否则,就无法作为证券市场未来系统风险性的无偏差估计。利用CHOW检验方法对2004年1月至12月间在深圳交易所上市的25只股票的交易数据和深证综合指数做实证分析表明,在我国证券市场上单只股票贝塔系数具有稳定性,与大部分学者观点不同;同时,又对在上海证券交易所上市的金融行业7只股票和传播与文化产业6只股票的日数据与上证综指做回归,并计算F值,说明金融行业比传播与文化产业的贝塔系数的稳定性差。     

对我国货币供给有效性的实证分析

近年来 ,中国为刺激经济复苏 ,连续多次下调存款利率及法定存款准备金率 ,进行大规模的货币扩张 ,但效果不显著。通过建立货币及其相关因素的经济模型 ,使中国的货币供给更为有效 ,但存在时滞。最后强调中国经济在未来几年有通货膨胀的可能性。     

Quarterly Earnings Announcements and Market Risk Adjustments

We examine (1) whether there is a shift in beta for individual securities around quarterly earnings announcements, and (2) whether these beta changes relate to certain characteristics of the firms. We find a statistically significant upward (downward) beta shift during the two-day earnings announcement period for 25 per cent (9 per cent) of a sample of 195 US firms. We also find that the beta shift at the time of the earnings announcement is significantly higher for small firms (i.e., more precise announcements).     

Decomposing the bias in time-series estimates of CAPM betas

We identify two sources of bias arising from time-series regression used to compute beta. This bias arises due to the classical error in variables problem and a ‘mechanical interaction’ which exists when the index comprises the asset of interest. Assuming that the market is proxied by a fixed-weight index, we demonstrate that the relative weighting of an asset within the index, and/or the magnitude of its idiosyncratic risk, directly biases the beta estimate for the individual stock and also for all stocks within the index. Via simulations, we show that the problem is most pronounced for markets with a small number of highly concentrated assets. Finally, we propose a procedure to reduce this bias and apply the methods to equity data.     

The Economic Convergence Performance of Central and Eastern European Countries

A critical discussion of a comparative growth analysis about Central and Eastern European (CEE) countries is performed. The main conclusion is that there was economic convergence for most CEE accession candidates, but not between them and Western Europe. Results do justify a separation into first and second-wave accession countries, but also undermine differences in Central and Eastern Europe between accession and non-accession countries.This paper critically examines theories and empirical studies for three types of convergence, namely , and club convergence. Each can be in absolute terms or conditional to the long-term equilibrium (steady state) for each country.Empirical results are provided for all types of convergence from 1996 to 2000, both with population-weighted and non-weighted data. The analysis is performed for differently framed country subgroups considering even Western Europe for better comparability. Once absolute convergence is found through a unit root test about a standard deviation time series of cross-sectional income per capita, the regression coefficient for initial income per capita with the average growth over the sample period as dependent variable ( convergence) establishes the speed of this process. The same method applies to the conditional version by using the distance of the income from the corresponding steady state instead of the level of GDP. Then Markov chain probability matrixes (club convergence) provide information about the past behaviour of the whole cross-sectional income distribution over time, but also about intra-mobility of single countries.     

一种基于相对风险的风险预算方法

风险预算是针对积极投资管理者进行的,所以我们预算和控制的风险主要来自于相对风险而不是绝对风险。本文中的风险预算方法则是在相对风险的基础上,利用边际跟踪误差、相对于基准的调整量、积极因子和积极beta系数等一系列相对概念。通过两个最优化模型,分别在战略资产配置和战术资产配置过程中,将风险配置于投资管理者和管理者资产,并且根据投资者,给定的管理者风险贡献和管理者实际风险贡献之间的误差,进行及时的动态调整,从而完成风险预算的整个过程。     

我国股市行业时变β系数研究

本文主要考察了我国股市13个行业的β系数及信息的影响。研究发现市场信息和行业信息对β系数都有影响,但影响的方向和大小因行业而异。进而对这些行业的β系数的信息非对称效应产生原因进行考察。仅有部分行业的β系数的信息非对称效应可由市场利空消息或行业利空消息解释。     

双寡头模型下的产品质量竞争与厂商决策

假定厂商面对非均匀分布的消费者以及随质量变动的成本，分析当消费者偏好分布为口（beta）分布时，厂商在利润最大化假设下的质量与价格决策，并进而分析在不同的消费者偏好分布下，高质量优势存在的可能性。     

A Reconsideration of Tax Shield Valuation

A quarter‐century ago, Miles and Ezzell (1980) solved the valuation problem of a firm that follows a constant leverage ratio L = D/S. However, to this day, the proper discounting of free cash flows and the computation of WACC are often misunderstood by scholars and practitioners alike. For example, it is common for textbooks and fairness opinions to discount free cash flows at WACC with beta input β _S = [1 + (1 ? τ)L]β_u, although the latter is not consistent with the assumption of constant leverage. This confusion extends to the valuation of tax shields and the proper implementation of adjusted present value procedures. In this paper, we derive a general result on the value of tax shields, obtain the correct value of tax shields for perpetuities, and state the correct valuation formulas for arbitrary cash flows under a constant leverage financial policy.     

Required Rates of Return for Corporate Investment Appraisal in the Presence of Growth Opportunities

Traditional methods of estimating required rates of return overstate hurdle rates in the presence of growth opportunities. We attempt to quantify this effect by developing a simple model which: (i) identifies those companies that have valuable growth opportunities; (ii) splits the value of shares into ‘assets‐in‐place’ and ‘growth opportunities’; and (iii) splits the equity β into β for ‘assets‐in‐place’ and ‘growth opportunities’. We find growth opportunities for UK companies over the 1990–2004 period to average 33% of equity value. Incorporating the effect of growth opportunities, the average cost of capital for investment purposes falls by 1.1 percentage points.