Goodness‐of‐fit methods for matched case‐control studies

The authors propose graphical and numerical methods for checking the adequacy of the logistic regression model for matched case‐control data. Their approach is based on the cumulative sum of residuals over the covariate or linear predictor. Under the assumed model, the cumulative residual process converges weakly to a centered Gaussian limit whose distribution can be approximated via computer simulation. The observed cumulative residual pattern can then be compared both visually and analytically to a certain number of simulated realizations of the approximate limiting process under the null hypothesis. The proposed techniques allow one to check the functional form of each covariate, the logistic link function as well as the overall model adequacy. The authors assess the performance of the proposed methods through simulation studies and illustrate them using data from a cardiovascular study.     

随机变量投影的一种应用

利用随机变量的投影关系,定义了偏方差矩阵,从而导出了逆方差阵元素的一种形式在随机变量是正态的条件,它为判别条件独立性有方便的操作办法。     

民营上市公司实际控制人与现金股利研究

实际控制人对上市公司的现金股利分配具有重要影响。本文以2004-2006年沪深证券交易所的民营上市公司为样本,对实际控制人与现金股利之间的关系进行了实证研究。研究结果证实,实际控制人通过IPO的方式获得上市公司的控制权同现金股利显著正相关,控制权与现金流权同现金股利显著正相关,控制权与现金流权发生分离和采用金字塔控制方式同现金股利显著负相关。而且,与通过非IPO的方式获得上市公司控制权的实际控制人相比,通过IPO的方式获得上市公司控制权的实际控制人其控制权与现金流权对现金股利的影响更加显著,控制权与现金流权发生分离和控制方式为金字塔时发放的现金股利更多。     

交叉上市、治理环境与上市公司超额现金价值

从超额现金持有价值的角度,将治理环境和治理约束的改变引入到公司治理与公司价值的研究框架中。以1998年至2011年中国A股上市公司的非平衡面板数据为研究对象,采用Dittmar等提出的公司超额现金持有量估计方法,在回归方程中加入交叉上市的虚拟变量,对比分析A股与AB股、AH股以及发行ADR企业所处治理环境的不同对超额现金持有价值的影响。实证结果表明,中国上市公司的超额现金持有普遍存在折价现象;只在A股市场上市的企业超额现金资产的边际价值为负;既在A股市场上市同时又在B股市场或H股市场交叉上市的企业,超额现金资产的折价程度降低,且私有上市公司的折价降低程度更加明显。上述结果表明严格的治理环境和治理约束有助于改善公司治理和降低现金资产折价;中国的A股上市公司,特别是私有公司,可以通过交叉上市增加外部治理约束降低现金资产的折价程度,提升公司价值。     

会计稳健性与自由现金流的代理成本:基于公司投资行为的考察

会计稳健性要求及时确认损失的发生、延时确认收益的发生.一般认为会计稳健性较高的公司,信息不对称程度低,具有较高的公司治理水平.本文从公司投资行为视角考察会计稳健性对自由现金流代理成本的影响.通过研究发现:非效率投资在我国企业普遍存在;高的会计稳健性具有抑制非效率投资的作用,并在一定程度上降低了自由现金流的代理成本.但要彻底解决非效率投资问题,仍需进一步规范公司的现金持有政策,并完善公司治理结构.本文的研究也为控制自由现金流的代理成本提供了一种可行性的解决方案.     

四方控制权制衡、自由现金流量与过度投资行为

目前关于过度投资的研究主要集中在债务融资对过度投资行为的影响上,关于公司控制权制衡与过度投资行为关系的研究基本还是空白。本文通过对自由现金流量和过度投资行为的进一步分析,从控制权制衡角度出发,构建以股东、董事会、监事会和债权人四方为主的过度投资行为制衡模型,研究我国上市公司控制权制衡、自由现金流量与过度投资行为之间的关系。     

Performance of weather-conditional rebates under different risk preferences

Retailers who sell seasonal products often face challenges in demand management due to weather uncertainty. In many cases, they make their ordering and pricing decisions prior to the regular selling season but the vast majority of sales do not occur until after the season starts, during which unfavorable weather conditions may result in high monetary losses. To protect against such adverse financial outcomes, retailers may offer weather-linked promotions such as weather rebates and induce customers to make early purchases. Specifically, weather-conditional rebates are incentives offered in an advance promotional period to be paid to the early buyers if the weather state in the regular season is unfavorable. In the presence of seasonal weather uncertainty, risk attitudes of retailers and buyers may play an important role on the effectiveness of these promotions. In this paper, we analyze the performance of weather-conditional rebates by explicitly considering the impact of different risk behaviors. First, we study the case in which the retailer and customers are risk-neutral and show that the weather-conditional rebates are effective in increasing the retailer's profits. Under the assumption of the retailer's risk-neutrality, we conduct a simulation study to investigate the impact of customers' alternative early-purchase behaviors on the performance of the rebate program. Next, we consider a risk-averse retailer. We model the retailer's risk aversion primarily in the mean–variance framework and find that the rebate program can be designed to increase the mean profit and reduce the profit variance simultaneously. Furthermore, by combining the rebate program with a financial instrument such as binary weather options, the retailer can obtain greater benefits from weather-conditional rebates.     

经济政策不确定性与企业现金持有策略——基于中国经济政策不确定指数的实证研究

研究经济政策不确定性对企业现金持有策略的影响,发现企业在经济政策不确定性上升时会增持现金,这种现金增持行为在融资约束较为严重、股权集中度较低以及学习能力较差的企业中更加明显.此外,本文还采用中介效应分析方法,发现企业在经济政策不确定性上升时增持的现金,有一部分是以放弃当前投资机会为代价的,被放弃的投资机会构成了企业在经济政策不确定性上升时增持现金的机会成本.     

Enriching Resources for the Poor: Lessons from the Philippines

The paper provides an overview of the poverty situation in the Philippines, followed by a brief profile and assessment of two anti‐poverty programs: the Kapit‐Bisig Laban sa Kahirapan‐Comprehensive and Integrated Delivery of Social Services (KALAHI‐CIDSS) program and the Pantawid Pamilyang Pilipino Program (4Ps). Official statistics disclose that the global economic crisis in 2008 adversely affected Filipino households, leading to higher levels of poverty especially in rural areas. In response, government introduced an Economic Resiliency Program with social protection as one component. Sixty‐six social protection programs were launched, including the two under review. KALAHI‐CIDSS and the 4Ps apply poverty reduction strategies that focus on the development of human and social capital, rather than economic capital. They involve processes and relationships that aim to improve the other dimensions of poverty, such as lack of access to opportunities or deprivation of basic human necessities. Qualitative and quantitative reports describe generally favorable outcomes from both programs. However, these gains at the household level need to be supported by relevant policy, enhanced public services and badly‐needed infrastructure programs from government, in order to sustain achievements culled from social protection programs and attain broader developmental impacts.     

Managing Logistics in Regional Banknote Supply Chain Under Security Concerns

We study the logistics problem faced by Regional Branches (RBs) of a central bank in managing the currency supply under security concerns. While making banknote supply decisions to Sub‐Branches (SBs), the management of RB must achieve two goals simultaneously: (i) guarantee that each SB has sufficient inventories of all denominations of banknotes to satisfy the demands from all commercial banks within its service area, and (ii) control the annual spending on this banknote supply operation. Due to security concerns, the following methods are implemented in the process of transporting banknotes: (i) the capacity of a cash truck is limited by the total face value (instead of the physical space) of banknotes, and (ii) empty decoy trucks are deployed along with the trucks filled with banknotes. After deriving a polynomial‐time strategy to guarantee an optimal solution for the special Bin‐Packing Problem faced in this study, we provide an exact formulation for the RB's supply planning problem. We also propose several polynomial‐time algorithms for deriving either optimal or near‐optimal solutions for the problem under different settings. Using the weekly demand data obtained from the central bank, we verify the performance of our algorithms, and analyze the impacts of changes in these features and in the fleet capacity on the total cost incurred by an RB under various scenarios.