股票价格服从不对称跳跃-扩散过程的期权定价模型

经典期权定价公式B—S模型假设股票价格服从连续的几何布朗运动,然而,经验研究表明股票价格常常发生跳跃式的变化,这主要是由于股市上常出现一些重大的事件导致的。通过对期权市场出现的“隐含波动率微笑”现象进行观察和研究,可以发现引起股票价格上升或者下跌的跳跃式变化往往是不对称的。为简单起见,在假设跳跃幅度服从均匀分布假设前提下,初步建立起股票价格服从不对称跳跃-扩散过程期权定价模型。     

金融市场的分形特征分析

本文阐述了传统金融系统的ＥＭＨ理论,在ＥＭＨ假设条件下,认为市场是均衡的,服从正态分布的。但实际上,市场收益率分布明显偏离高斯分布,呈现一种“胖尾特性”。通过分形理论分析及Ｈｕｒｓｔ指数刻划,论证了金融市场的分数布朗运动特性。     

中国证券投资基金的最优套利策略研究

在基金经理人效用函数为指数效用函数、投资基金价格服从几何布朗运动的条件下，基于市场存在交易费用及投资期限无限情况下的最优套利策略，就各参数对最优交易策略的影响进行分析，并对在无风险资产和多种风险资产之间进行资产组合。     

中国股票市场透明度改革效果的理论与检验

文章通过观察我国股票市场微观结构特征,在理性预期的分析框架内,用贝叶斯模型解释交易成本、信息不对称和价格发现效率,给出交易前透明度增加对市场微观结构产生影响的三个假设。在此基础上,选择沪深300指数样本股票,采用三种不同检验方法对假设进行实证检验。检验结果表明:交易前透明度的增加,减少了交易成本,降低了股票交易中的信息不对称,提高了市场的价格发现效率。     

中国IPO市场存在承销商托市吗

本文采用修正后的Ruud(1993)收益率分布检验法对中国A股市场上IPO股票上市后短期收益率分布进行了检验.考虑抑价极大值会使样本收益率分布明显右偏,本文运用剔除抑价极大值后的样本对不同定价机制下的IPO后市短期收益率分布进行了正态性检验.我们发现,IPO股票上市后的短期收益率分布不能拒绝正态分布的零假设.这说明中国IPO市场不存在明显的承销商托市,目前高抑价的原因不能用承销商托市行为来解释.     

噪声交易与市场渐进有效性

投资者的非理性行为在市场渐进有效的进程中扮演了怎样的角色-现有文献并没有给出直接的研究和明确的结论.本文对上证50指数所代表的子市场的噪声交易情况进行了度量,同时构建状态空间方程并采用Kalman滤波法测度了该市场的渐进有效性,进而研究投资者噪声交易对我国市场渐进有效性的水平及其波动的影响.研究发现,我国市场整体上趋于有效,噪声交易的平均水平在各时期比较平稳;噪声交易会起到微弱的降低市场有效性水平的作用,增加渐进有效性的短期波动,但是从长期看并不能影响市场趋于有效的趋势.本文结论说明,投资者的非理性行为并不是造成我国资本市场非有效的根本原因,但是非理性行为也在短期内给市场的有效性进程造成阻滞.     

Bootstrap方法在空间经济计量模型检验中的应用

本文提出采用Bootstrap方法对空间经济计量模型的残差分布进行Moran’s指数,最大似然LM-Error及LM-Lag统计量的模拟检验,可用于空间经济计量模型的(事先)确定及(事后)验证。通过两个实例表明,在回归误差服从独立分布的假设下,有别于大样本理论分布的经典检验法,Bootstrap方法能有效地解决空间经济计量模型残差分布不确定时,模型中变量间空间相关性的检验问题。     

股票市场收盘集合竞价对市场有效性的影响——来自深圳证券交易所的证据

笔者基于深圳证券交易所于2006年7月1日收盘采用集合竞价事件,选择事件日前后两个窗口期的交易数据,运用价格同步法分析方法,研究了收盘集合竞价对市场有效性的影响。研究发现:收盘采用集合竞价后,市场交易量、波动性和相对买卖价差均有显著下降,市场模型的解释力显著提高;第二阶段和第三阶段回归方程中的关键参数检验,以及构造的虚拟事件的稳健性检验结果均证明收盘集合竞价显著促进了市场有效性。     

基于价值估计差异和交易不对称的证券价格一般均衡模型

本文发展并建立了一个基于价值估计差异和市场交易不对称的证券价格一般均衡模型。这个模型不依赖对证券基础价值的假设,也不依赖市场有效性的假设,可以解释针对主流金融学提出的市场无效现象。     

资源保障性对质量改进有效性影响实证研究

文章为提高企业质量改进有效性进而预防质量危机,在对资源保障性对质量改进有效性影响关系文献分析基础上,提出了资源保障性对质量改进有效性影响的理论假设,并构建了相应的概念模型;通过问卷调查获取研究数据,利用SPSS19.0及AMOS18.0对数据进行了信度分析及效度检验,并采用结构方程模型对数据进行统计分析,验证了概念模型和理论假设的正确性,并探讨了资源保障性对质量改进有效性的作用机理。     

Rational Expectations and Price Determination in the US Oats Market

This paper develops a simultaneous rational expectations model of the US oats market Consistent estimates of the structural parameters are obtained by the instrumental variables method and 15 of 16 parameter estimates are significant at the 5 per cent level Estimated elasticities suggest that hedged stocks are more responsive to price changes than unhedged stocks, and that consumption demand for oats is more responsive to income changes than to changes in price. Post-sample forecasts of the spot price derived from this model are employed to test the semi-strong form efficient markets hypothesis (EMH), although the futures price outperforms the model as a predictor of the spot price. Hence the EMH cannot be rejected     

The Semi-Strong Efficiency of the Australian Share Market*

This paper tests the weak and semi-strong forms of the Efficient-Markets Hypothesis (EMH) using data on the Australian skate market in the 1980s. The tests are based on aggregate share price indexes and the semi-strong efficiency tests use macroeconomic data The weak-form tests examine the autocorrelation structure of share returns and test for unit roots in share prices. The data are found to be consistent with the EMH.     

Re-examining the Turkish stock market efficiency: Evidence from nonlinear unit root tests

This paper re-examines the efficient market hypothesis (EMH) in the Turkish stock market by utilizing the recent developments in nonlinear unit root tests. To this end, we first employ the linearity test developed by Harvey et al. (2008) and then carry out the nonlinear ESTAR unit root test recently developed by Kruse (2011). The results show that Borsa Istanbul stock price index series have nonlinear behavior and follow the random walk (non-stationary) process, supporting the EMH in Turkish stock market which has weak-form efficiency.     

Robust Volatility Estimation with and Without the Drift Parameter

We find the closed form solution for the joint probability of the running maximum and the drawdown of the Brownian motion with a non-zero drift parameter at a random time that is exponentially distributed and independent of the Brownian motion. This characterization leads us to come up with a robust method of estimating volatility using open, high, low and closing prices. We rigorously show the independence of robust volatility estimators based on extreme values of asset prices relative to the standard robust volatility estimator based on closing price alone. We further prove that the proposed robust volatility ratio is unbiased with no drift parameter. Moreover, we find that the robust volatility ratio with a non-zero drift parameter has only a second order effect. We have shown that our proposed extreme value robust volatility estimator is 2–3 times relatively more efficient when compared to the classical robust volatility estimator based on Monte Carlo simulation experiment. On the empirical side, we test the proposed robust volatility ratio based on high and low prices on different asset classes like stock indices, exchange rate and precious metals.

     

Testing the Option Value Theory of Irreversible Investment

This article statistically tests the option theory of irreversible investment. Using contingent claims valuation, we derive the value of options to invest in capacity, where the projects are endogenous to the economic circumstances prevailing at the investment date. We then test whether decisions made by Canadian copper mines are compatible with the trigger price implied by the theory. Our model explains investment size and timing satisfactorily from a statistical and an economic point of view; simulations with a mean-reverting process suggest that the results do not depend crucially on the assumption that price follows a geometric Brownian motion.     

PRACTICAL GUIDE TO REAL OPTIONS IN DISCRETE TIME*

Continuous time models in the theory of real options give explicit formulas for optimal exercise strategies when options are simple and the price of an underlying asset follows a geometric Brownian motion. This article suggests a general, computationally simple approach to real options in discrete time. Explicit formulas are derived even for embedded options. Discrete time processes reflect the scarcity of observations in the data, and may account for fat tails and skewness of probability distributions of commodity prices. The method of this article is based on the use of the expected present value operators.     

石化权证在GARCH模型下的实证检验

股票价格的波动率特征是股票衍生品价格的决定性因素。Black&Scholes假设股票价格服从几何布朗运动,其重要的假设条件是波动率为一个常数。但是,越来越多的实证研究结果表明,股票收益率存在显著的尖峰厚尾现象,其波动率存在明显的时变性特征。因此,放宽波动率恒定条件,并且研究股票波动率的变动特征,对认购权证的正确定价具有重要意义。     

Market clearing, utility functions, and securities prices

Summary. We prove the existence of equilibrium in a continuous-time finance model; our results include the case of dynamically incomplete markets as well as dynamically complete markets. In addition, we derive explicitly the stochastic process describing securities prices. The price process depends on the risk-aversion characteristics of the utility function, as well as on the presence of additional sources of wealth (including endowments and other securities). With a single stock, zero endowment in the terminal period, and Constant Relative Risk Aversion (CRRA) utility, the price process is geometric Brownian motion; in essentially any other situation, the price process is not a geometric Brownian motion.JEL Classification Numbers: D52.This paper is part of my Dissertation (UC Berkeley). I am very grateful to my advisor Professor Robert M. Anderson. I also would like to thank Steve Evans, Roger Purves, Jacob Sagi, Chris Shannon and the participants of the 2002 NBER General Equilibrium Conference at the University of Minnesota (Minneapolis) for very helpful discussions and comments. This work was supported by Grant SES-9710424 from the National Science Foundation.     

结合新产品扩散特征的实物期权定价模型研究

现有实物期权定价模型未能考虑新产品销售量所呈现的扩散特征,模型的分析结果与实际情况有较大差距。文章假设新产品价格服从几何布朗运动,并以Bass模型预测新产品的销售过程,运用二叉树方法,构建了离散时间状态下结合新产品扩散特征的实物期权定价模型,并得到新技术采用的最优时机。     

Simultaneity, Rationality and Price Determination in US Live Cattle

The results of recent research on the informational efficiency of the US live cattle futures market are ambiguous. Moreover, simultaneous, rational expectations models of spot and futures markets for non-storables are lacking in the literature. This paper addresses both issues: by developing a simultaneous rational expectations model of the US live cattle market, with functional relationships for short hedgers, long hedgers, net short speculators and consumers, the paper employs a wider information set than in previous research and it thus provides a more powerful test of the efficient market hypothesis (EMH). Tests indicate the possible presence of non-linearities in the long hedging and net short speculation equations.
The results suggest first, that there is support for Working's hypotheses of selective and operational hedging, for short and long hedgers respectively, second that speculators may be noise traders or risk-loving (although the non-linear version of the speculation function partially corrects this anomaly), and third that beef is a normal good while corn is a complementary input. Time-varying volatility is represented as an EGARCH ( p , q ) process. Post-sample, this model does not significantly outperform the futures price in spot price forecasting, implying non-rejection of the EMH.