GMM,GEL, Serial Correlation,and Asymptotic Bias

For stationary time series models with serial correlation, we consider generalized method of moments (GMM) estimators that use heteroskedasticity and autocorrelation consistent (HAC) positive definite weight matrices and generalized empirical likelihood (GEL) estimators based on smoothed moment conditions. Following the analysis of Newey and Smith (2004) for independent observations, we derive second order asymptotic biases of these estimators. The inspection of bias expressions reveals that the use of smoothed GEL, in contrast to GMM, removes the bias component associated with the correlation between the moment function and its derivative, while the bias component associated with third moments depends on the employed kernel function. We also analyze the case of no serial correlation, and find that the seemingly unnecessary smoothing and HAC estimation can reduce the bias for some of the estimators.     

基于定单流的动态投资策略及实证

引入定单流指标捕捉资金流向, 提出定单冲击系数刻画资金流向的变化速度, 从金融市场微观结构视角, 建立了基于定单流的动态投资策略。从投资者期望效用最大化角度出发, 通过构建Lagrange函数, 推导出了动态投资策略的最优投资权重。选取2009年6月1日--2009年7月31日深证综指指数股票日数据进行实证分析, 实证结果表明, 基于定单流的动态投资策略能取得更好的投资收益。基于成对数据的t检验结果表明, 基于定单流的动态投资策略能获得超额收益。本文的研究为金融市场微观结构视角下的投资策略构建提供了新的方向。     

Simple Finite Horizon Bubbles Robust to Higher Order Knowledge

An asymmetric information model of a finite horizon “nth order” rational asset price bubble is presented, where (all agents know that)ⁿ the asset is worthless. Also, the model has only two agents, so the first order version of the bubble is simpler than other first order bubbles in the literature.     

Higher Order Uncertainty and Information: Static and Dynamic Games

Weinstein and Yildiz (2007) have shown that in static games, only very weak predictions are robust to perturbations of higher order beliefs. These predictions are precisely those provided by interim correlated rationalizability (ICR). This negative result is obtained under the assumption that agents have no information on payoffs. This assumption is unnatural in many settings. It is therefore natural to ask whether Weinstein and Yildiz's results remain true under more general information structures. This paper characterizes the “robust predictions” in static and dynamic games, under arbitrary information structures. This characterization is provided by an extensive form solution concept: interim sequential rationalizability (ISR). In static games, ISR coincides with ICR and does not depend on the assumptions on agents' information. Hence the “no information” assumption entails no loss of generality in these settings. This is not the case in dynamic games, where ISR refines ICR and depends on the details of the information structure. In these settings, the robust predictions depend on the assumptions on agents' information. This reveals a hitherto neglected interaction between information and higher order uncertainty, raising novel questions of robustness.     

煤炭行业上市公司股权结构对企业技术效率的影响研究

运用随机边界分析方法,计算了我国11家煤炭上市公司的技术效率;建立了股权结构与技术效率之间的函数关系,以煤炭上市公司2001~2006年间的数据为样本,运用回归分析方法,验证了煤炭上市公司的股权集中度与技术效率之间呈显著的"U"型关系。     

Inventory control under different forms of uncertainty: Ambiguity and stochastic variability

Inventory decision makers routinely face ambiguity due to the psychological awareness that there is unknown information about salient events that is knowable in principle. Researchers on inventory control behavior in the face of uncertainty have primarily focused on uncertainty due to stochastic variability. However, most decision situations in the naturally occurring world involve both forms of uncertainty—ambiguity and stochastic variability. We report the results of two experiments that partial out the effects of ambiguity and stochastic variability by orthogonal manipulation of these two forms of uncertainty in a newsvendor task. Contrary to established mathematical models of decision making under uncertainty, increased ambiguity results in increased mean absolute percentage error, and a corresponding decrease in profit. We also find a systematic bias toward underordering associated with increased ambiguity, which is over and above the bias associated with increased stochastic variability. We do not see evidence for learning with repeated play, so that the effects of induced ambiguity appear to persist. Finally, based on our findings, we suggest measures that managers can use to ameliorate the effects of ambiguity.     

Strict Stationarity Testing and Estimation of Explosive and Stationary Generalized Autoregressive Conditional Heteroscedasticity Models

This paper studies the asymptotic properties of the quasi‐maximum likelihood estimator of (generalized autoregressive conditional heteroscedasticity) GARCH(1, 1) models without strict stationarity constraints and considers applications to testing problems. The estimator is unrestricted in the sense that the value of the intercept, which cannot be consistently estimated in the explosive case, is not fixed. A specific behavior of the estimator of the GARCH coefficients is obtained at the boundary of the stationarity region, but, except for the intercept, this estimator remains consistent and asymptotically normal in every situation. The asymptotic variance is different in the stationary and nonstationary situations, but is consistently estimated with the same estimator in both cases. Tests of strict stationarity and nonstationarity are proposed. The tests developed for the classical GARCH(1, 1) model are able to detect nonstationarity in more general GARCH models. A numerical illustration based on stock indices and individual stock returns is proposed.     

中国区域经济与高等教育均衡关系的动态模型

本文从估计均衡关系的角度出发,定量的分析了我国区域高等教育与经济发展之间的非均衡状况,并考虑了几个典型地区非均衡程度的动态变化趋势和整体非均衡程度的动态变化趋势,得到了整体非均衡性程度呈下降趋势的结论。     

指令不均衡与股票收益关系研究——基于大规模数据分位数回归的实证

在指令不均衡与股票收益关系研究中,常常遇到两个困难：第一,不同市场环境下,前者对后者存在异质影响;第二,往往涉及大规模数据处理。为此,运用大规模数据分位数回归的方法,一方面揭示不同分位点处指令不均衡对股票收益的异质影响,细致刻画两者之间关系;另一方面适应大规模数据建模要求,得到更为可靠的结果。以上证A股和深证A股为研究对象,通过大规模数据分位数回归方法,得到了比均值回归更多有用信息。实证结果表明：第一,在高分位点处,滞后1期指令不均衡对股票收益具有正向影响且呈现上升趋势,而在低分位点却具有负向影响;第二,控制当期指令不均衡后,滞后期指令不均衡对股票收益具有负向影响,且随着分位点的增加呈现下降趋势。这些结果意味着,指令不均衡对股票收益具有一定的解释能力和预测能力。     

跟单服务与溢短交易驱动下产能分享供应链均衡策略选择

考虑由于信息不对称等原因导致的产能分享双方订单与实际交付不一致的情形,本文构建了由产能买方,产能卖方和第三方跟单服务商组成的产能分享供应链系统,并研究“溢短交易”和“跟单服务”对产能交付率提升发挥的作用。考虑产能卖方决策是否选择溢短交易模式,产能买方决策是否接受跟单服务,本文采用博弈论分析了产能买卖双方的占优策略以及双方的均衡策略组合。研究发现,溢短交易和跟单服务都可以降低产能分享的加入门槛,使得更多企业加入到产能分享中。当次品率相对较高,或跟单服务效果相对较好时,买卖双方倾向于接受跟单服务,采取普通交易模式;相反,当次品率相对较低,或跟单服务效果相对较差时,买卖双方倾向于采取溢短交易模式,不接受跟单服务。本文进一步给出了溢短交易和跟单服务的均衡策略及其条件,为产能买卖双方对合作对象的选择及相关决策提供了依据。     

Static and Dynamic Pricing of Excess Capacity in a Make‐to‐Order Environment

We consider a make‐to‐order manufacturer that serves two customer classes: core customers who pay a fixed negotiated price, and “fill‐in” customers who make submittal decisions based on the current price set by the firm. Using a Markovian queueing model, we determine how much the firm can gain by explicitly accounting for the status of its production facility in making pricing decisions. Specifically, we examine three pricing policies: (1) static, state‐independent pricing, (2) constant pricing up to a cutoff state, and (3) general state‐dependent pricing. We determine properties of each policy, and illustrate numerically the financial gains that the firm can achieve by following each policy as compared with simpler policies. Our main result is that constant pricing up to a cutoff state can dramatically outperform a state‐independent policy, while at the same time achieving most of the increase in revenue achievable from general state‐dependent pricing. Thus, we find that constant pricing up to a cutoff state presents an attractive tradeoff between ease of implementation and revenue gain. When the costs of policy design and implementation are taken into account, this simple heuristic may actually out‐perform general state‐dependent pricing in some settings.     

The Effects of Computerized Visual Feedback Using Flashing Lights on Order Selection in Large Industrial Settings: Productivity,Accuracy, and Cost Justifications

This report from the field concerns a pilot study that used computerized visual feedback in the form of flashing lights to inform order selectors in an auto parts distribution center to fulfill store orders. Compared to paper pick lists, order selection performance and accuracy reliably increased when the delivery method was the flashing lights. The role of the organizational behavior management participant in industrial settings in designing interventions that increase accuracy and productivity was examined. More than just the intervention, the cost justification was part of the decision-making process about whether to continue with the intervention.