Abstract:This paper introduces economic policy uncertainty into a stochastic discount model． Via parameter calibration and static analysis，the dynamic characteristics of stock risks resulted from different policy uncertainties are investigated． The channel through which policy uncertainty affects stock risk is simulated empirically， and the effect of policy uncertainty on stock risk is simulated by portfolio analysis to verify the applicability of the theoretical model in China． Finally，the panel model is used to quantitatively analyze the relationship between policy uncertainty and stock risks． The results show that policy uncertainty can improve stock risk through the enterprise’s cash flow，discounting factors and correlation coefficient，and the improvement is still significant after controlling traditional risk factors，corporate heterogeneity，and external environmental factors． Companies that are non-state-owned，having lower return on invested capital and lower asset growth rate manifest greater stock risks when policy uncertainty is higher． The magnitude of influence of policy uncertainty on stock risk is larger when the economy is weaker and the policy environment is more unstable．

Abstract:Based on a stochastic volatility and stochastic jump intensity ( SVSJ) option pricing model，this paper gives a thorough study of the S＆P 500 index options． The empirical results show that significant jump premiums only exist in short term out-of-the-money options and short term at-the-money options，and the jump premium is much larger than the volatility premium． With different model specifications，the paper finds that although the contribution of jump variances to the total variance is quite small，jump premium accounts for a large proportion of total risk premium． For all model specifications，all the model sperform better in high volatility periods than in low volatility periods． Among these models，the SVSJ model has the greatest pricing efficiency．

Abstract:Exploiting the staggered removal of short-sale bans in China，the paper examines how short-selling affects share overvaluation from the perspective of heterogeneous beliefs． The study finds that removal of shortsale bans can decrease share overvaluation． Short-sellers use both public information and private information to trade，contributing to the price discovery． Furthermore，short-sellers release more pessimism or negative information by short selling more stocks，which can decrease share overvaluations． Short-sellers trade to decrease overvaluation by selling stocks with higher contemporaneous returns and private information． The study provides new and direct evidences for worldwide arguments on this problem: whether short-selling can improve stock pricing efficiency or not． At the same time，this study provides a unified conclusion to the information sources of short-sellers．

Abstract:Investors can sell short on designated stocks in China’s stock market since March 2010 when the CSＲC relieved the short sale constraint． The paper provides a quasi-natural experiment to examine whether short selling pressure can discipline the controlling shareholder’s exploitation． Using a sample of Chinese listed firms during 2007 － 2014，the results show that short selling pressures from the removal of the short sale constraints have a governance effect on the pursuit of private benefit of controlling shareholders． Downside risk is the economic mechanism through which short-selling threat disciplines the controlling shareholders． The governance effect from short sale is much stronger when other corporate governance mechanisms are weak． The cross-sectional tests suggest that the higher the proportion of shares the controller holds or the higher bankruptcy risk of the firm faces，the more reduction in the exploitation of controllers in pilot firms after the removal of short sale constraint． This paper provides further insight into the discipline effect of short selling on controlling shareholders in pursuing private benefits，and contributes to the literature on the effects of the removal of the short selling constraints on the real economy．

Abstract:This paper examines whether investor sentiment expressed in online user generated content ( UGC) in the stock message boards of Easymoney． com has a predictive power for Chinese stock market． Naive Bayes classifier is used to obtain the expectation of every message，and then a new indicator of investor sentiment is put for ward that combines the idea of bullishness and investor attention． Granger causality test，instantaneous Granger causality test and intertemporal regression analysis are applied to study the predictability of investor sentiment for stock returns，volatility，and trading volume． It is found that investor sentiment has no predictable power for returns，volatility，or trading volume; while investor sentiment does have a significant positive effect on the contemporaneous stock price，and disagreement of investor sentiment can affect contemporaneous trading volume． Inventor sentiment using the messages before market opening has the predictive power of open price，and inventor sentiment from the trading hours is more valuable for closing price and trading volume． Moreover，stock returns are the Granger cause of investor sentiment． Our results can help to understand the behavior of investors and their effects on stock market．

Abstract:The industry of Small Loan Companies ( SLCs) is developing very fast in China，but the problem of financing difficulties of Small and Micro Businesses is still serious because of Mission Drift in SLCs． Most studies examine Mission Drift from the perspective of financial sustainability; this paper intends to investigate it from the perspective of Ｒelationship Lending and Market Structure． By building a theoretical model，it finds that relationship lending and a competitive market structure are desirable，if SLCs are to supply more loans to satisfy the demand of Small and Micro Businesses and avoid Mission Drift． Furthermore，the paper analyzes SLCs in a representative municipal area of China，and believes that the reason of Mission Drift is insufficient use of the technology of relationship lending by SLCs，and the highly monopolized microcredit market．

Abstract:The paper studies regression analysis for interval data which are obtained by packaging point data． The existing methods of regression analysis for interval data only consider the endpoints of the intervals． This study focuses on how to use the point data within intervals sufficiently． Firstly，when the error of the regression model for point data satisfies the supposed three characteristics，the error of the regression model for interval data also follows the three characteristics． Then，based on the descriptive statistics of interval symbolic data，a novel approach of estimating the parameters of the regression model is proposed． A method is given to predict the interval values of the dependent variables． Finally，a simulation experiment and an application case are performed following the proposed methodology． The results indicate a better performance of our method than the existing CCＲM method．