大家谁也没有见过鬼，在这个前提下画鬼，只要大体上具备几个特征——恐怖、丑陋、怪异，还颇有几分像人（有五官、四肢），画出来的就是鬼。新古典金融理论就像画鬼。新古典金融模型争相勾画（但并不存在）的鬼就是在有效市场的假定下与资产的基本价值相等的资产价格。 金融市场是高度不确定的，金融市场上的不确定性或不确定性因素有多种，这诸多不确定性意味着金融市场几乎是最不具备条件构造模型（尤其是数学模型）的，但新古典金融理论没有条件创造条件，它几乎排除了所有不确定性才建立起画鬼式的新古典资产定价模型：用“市场纪律”（被动接受价格）排除了交易者定价的不确定性；用理性行为假定排除了行为模式的不确定性；用均值回避了目标值的不确定性；用“代表性主体行为分析”排除了主体角色的不确定性；用相同的信念和共同知识排除了主体认知程度甚至认知内容上的不确定性。 金融市场的不确定性可以分为两类，一类是来自主体认知、预期、角色的内在不确定性，一类是来自外部的消息等外在不确定性。比较而言，内在不确定性是根本的，它每时每刻都在影响金融市场，如股票价格时刻都在变动。新古典金融理论通过上述假定几乎釜底抽薪式地规避掉了内在不确定性，规避掉金融市场的内在不确定性后再把金融市场作为不确定性市场来分析，这就是新古典金融理论的荒谬之处。它的某些模型如CAPM，在理性预期、有效市场等强假定下，已经将不确定性市场变成了确定性市场。 新古典金融理论的根本问题在于没有勇气面对真正的不确定性，准确地说，新古典金融理论在做它们根本没有可能做好的事情：对金融资产定价给出精确的模型。

：目前我国常用的三大经典基金绩效考核模型都是以均值－方差CAPM模型为基础，而均值―方差CAPM模型中的系统性风险只考虑二阶矩风险即波动率，忽略了高阶矩风险。本文通过在传统CAPM模型中加入零成本的负协偏度投资组合和零成本的正协峰度投资组合作为高阶矩风险溢价重新解释基金风险与收益间的平衡关系,发现众多基金的投资组合中都存在负协偏度风险，基于高阶矩的考核模型优于基于传统CAPM的考核模型。

探讨CAPM中风险资产市场组合的概率分布和均值估计问题。在股票价格行为模型用维纳过程（又称布朗运动）表述的前提下，证明了CAPM中的市场组合服从加法逻辑正态分布的结论，进而给出了市场组合均值的三种估计。以此为基础进行CAPM的实证检验，才具有理论上的严密性。

最近20年来一些学者对CAPM理论模型检验的结果大都表明，股票的投资风险（或其收益）并非像该模型描述的那样由β系数唯一决定，还存在其他因素在股票投资风险中起影响作用。国内学者借助于横截面法的回归模型研究指出，股票的权益比率（D/E）、账面/市值价值比（BV/MV）与公司规模是决定股票投资风险除β系数外的三个主要经济变量。为了验证他们理论的正确性与精确性，该文率先运用模糊数学的聚类分析法，对上证市场随机选取10只样本股票的D/E、BV/MV、公司规模与股票投资风险相关性进行实证分析，并与用回归分析方法得到的β指数与风险关系进行比较研究。经研究进一步证实，股票投资风险并非唯一由β系数决定，股票的D/E、BV/MV及其公司规模应当成为β系数以外影响股票投资风险不可忽视的重要因素。本文研究的意义在于建议股票投资者，衡量股票投资风险不仅要考察股票的β系数，还应进一步考察股票的D/E、BV/MV和公司规模等。

We investigate the performance and characteristics of acquiring firms on 1148 M&A on the two Chinese stock markets from 1998 to 2003. Using the market model, the CAPM model and the buy-and-hold methods, we find significantly positive abnormal returns before (6 months) and upon M&A announcements, while the long-run abnormal returns (6 months) after M&A are insignificant. Within our sample, cash is the dominant payment method and the competition during M&A is low. The cross-sectional analysis on acquirers' market performance upon announcements shows that the political advantages of acquiring firms have a significantly positive impact on the acquirers' performance, while the economic advantages do not. Cross-provincial M&A and better corporate governance create value to acquiring firms. Finally, cash payment impacts positively and regulation development impacts negatively the performance of acquiring firms during M&A.

本文对 Daniel et al (1997) 的方法加以改进，提出了一个基于基金持股特性的绩效评估指标。实证分析结果表明，该指标与基于基金净值收益的指标相比，能够更好地反映基金的投资风格，使其评估结果更加合理。而采用能反应投资风格的3因子或4因子模型得到的基于基金净值收益的评估指标与采用CAPM模型得到的指标相比，虽然在择时能力的评价上其检验能力有所改进，但是在风险调整后收益的评价上，其检验能力并无明显改进。

资本资产定价模型（CAPM）被认为是金融市场现代价格理论的支柱之一，自从创立以来，其在各个领域得到了广泛的应用。然而，长期以来对CAPM的实证检验也争议不断，检验结果毁誉参半。本文评述了以往对CAPM的实证研究，并采用上海股票市场90家上市公司的数据作为样本对CAPM中的贝塔系数的波动状况进行了实证检验，结果发现所有股票贝塔系数的波动率都是显著异于零的，即贝塔系数在不同的时期会发生变化。实证分析中如果忽略了这一点，必将导致对CAPM检验失效。 Capital Asset Pricing Model is the backbone of the modern asset pricing theory of the financial market. Since it appeared, it is widely used in many fields. However, there are many disputations about the empirical tests of CAPM. Someone support it, but someone not. The authors review the past empirical tests of CAPM, and analyze 90 public companies in Shanghai security market. The conclusion helps to explain why some empirical tests of CAPM in the past fail.

This paper develops an integrated model of asset pricing and moral hazard. In particular, we combine a version of the Capital Asset Pricing Model (CAPM) with a multi-agent moral hazard model. The excess dollar returns for risky stocks, optimal contracts for managers (agents) that involve relative performance, and equilibrium stock prices are explicitly characterized. We show that the CAPM linear relation in terms of the expected dollar returns still holds in the presence of moral hazard and that our  is given by the ratio of the covariance between a firm’s stock return and the market return over the variance of the market return, with both returns adjusted for the compensation to the managers. The equilibrium price of a stock decreases with its idiosyncratic risk, but the expected excess dollar return of the stock is independent of it. Consequently, the risk premium, which is defined as the ratio of the excess return to the stock price, increases with idiosyncratic risk. We also show that the risk aversion of the principal in our model leads to less emphasis on relative performance evaluation than in a model with a risk-neutral principal. This result may shed light on why the empirical evidence for relative performance evaluation is mixed, even though the theoretical prediction based on a risk-neutral principal strongly supports it. In addition, we show that if the manager of a firm is compensated based solely on his own performance, then the expected dollar return of the firm increases with its idiosyncratic risk. This exercise illustrates that, in the presence of moral hazard, contracting plays a key role in the determination of the expected return of a stock. Furthermore, we show that under certain conditions, the equilibrium contract is a linear combination of the stock price and the level of the market portfolio.

In this paper, we develop a methodology to identify money managers who have private information about future asset returns. The methodology does not rely on a specific risk model, such as the Sharpe ratio, CAPM, or APT. Instead, it relies on the observation that returns generated by managers with private information cannot be replicated by those without it. Using managers’ trading records, we develop distribution-free tests that can identify such managers. We show that our approach is general with regard to the nature of private information the managers may have, and with regard to the trading strategies they may follow.

根据CAPM模型β成为通常收益率的解释因素，但自80年代以来，许多学者发现β缺乏对收益率的解释能力。1981年班茨和其他学者发现“小公司一月份效应”，即小公司有一系统较高的收益，尤其是在每年的一月份。这一现象与传统的CAPM公式相背。本文以1995-1997年深沪两市286只股票的周均收益率对中国股市进行了检验，得出中国不存在小公司效应，但数据支持一月份效应。通过这一研究深化了对股市有效性的认识。