Lies,damned lies and statistics: the accuracy of survey responses

That survey research is error prone is not a new idea and different varieties of non-sampling error have been investigated in the literature as well as consideration being given in many statistics textbooks to the issue of sampling error. The paper here considers research upon corporate environmental reporting. It compares information provided by corporate environmental reports with information that survey respondents claim their organization’s environmental report contains. This enables the accuracy of the claims to be assessed. Consideration is given to two different industries the Water industry and the Energy industry. Errors due to inaccurate reporting by survey respondents are shown to be relatively infrequent and respondents appear just about as likely to claim they report information that they do not, in fact, report as to fail to indicate that they report information that is, in fact, actually reported.     

SUPPLY CHAIN INFORMATION SHARING IN A VENDOR MANAGED INVENTORY PARTNERSHIP

Vendor Managed Inventory (VMI) involves the vendor making the replenishment decision for products supplied to a customer based on various inventory and supply chain policies. Information sharing between supply chain members is required in VMI. Sometimes VMI decisions are delayed and/or the information shared is inaccurate. This research examines the effects of information delay and accuracy, and the sharing of sales and forecast information in a VMI environment facing stationary and nonstationary demand. The simulation experiments show the impact of information delay, information inaccuracy, and information sharing on a variety of performance measures, including inventory levels and fill rates.     

A framework for the analysis of firm risk communication

In this paper, we propose a framework for the analysis of risk communication and an index to measure the quality of risk disclosure. Mainstream literature on voluntary disclosure has emphasized that quantity can be used as a sound proxy for quality. We contend that, in the analysis of the disclosure of risks made by public companies, attention has to be paid not only to how much is disclosed but also to what is disclosed and how.We apply the framework to a sample of nonfinancial companies listed in the ordinary market on the Italian Stock Exchange. To verify that the framework and synthetic index are not influenced by the two factors recognized in the literature as the most powerful drivers of disclosure behavior for listed companies, we use an OLS model. The regression shows that the index of disclosure quantity is not influenced either by size or industry. Thus, the synthetic measure can be used to rank the quality of the disclosure of risks.     

On efficiency of the ratio estimator

Summary The exact mean square error for the ratio estimator of a finite population total based on simple random sampling without replacement is shown to have an expected value less than that of the variance of the ratio estimator based on Midzuno’s scheme, under a usual super-population model.     

我国证券投资基金业绩的持续性研究

以上海证券交易所上市的10只同质的基金为样本,分三个阶段对基金业绩的持续性进行了实证分析,结果表明我国证券投资基金的业绩并不具有持续性.     

The Delphi method, impeachment and terrorism: Accuracies of short-range forecasts for volatile world events

Two experiments examined the effects of iterated polling and feedback on prediction accuracy for volatile world events using the Delphi paradigm. In both experiments, participants predicted rapidly changing geopolitical events. The first experiment occurred during the litigation surrounding the Clinton/Lewinsky affair in 1998. Results indicated that feedback improved individual and group accuracy for predictions of whether an event would occur. These types of predictions derived from group consensus were approximately 90% accurate, which was significantly higher than the average individual participant's accuracy. Neither polling nor feedback had much effect on time course predictions. The second experiment occurred during the American military action against the Taliban regime in Afghanistan in 2001. In Experiment 2, participants were polled three times to determine if increasing the number of iterated polls would improve Delphi accuracy. The results showed that accuracy improved from the first to the second poll but not from the second to the third. The groups predicted whether these scenarios would occur with approximately 75% accuracy, which was significantly higher than the accuracy of any individual participant. Once again, the Delphi procedure did not enhance time course predictions in Experiment 2.     

中国股市市盈率分布特征及国际比较研究

本文对市盈率的内涵、计算方法、区间确定等理论问题进行了剖解 ,针对中国股市流通股、非流通股并存等特征 ,对市盈率在中国股市的计算方法进行了分析 ;在此基础上对中国股市市盈率分布特征进行实证分析和国际比较研究 ,认为目前沪深股市泡沫成份已较少 ,市盈率在合理区间之内 ,中国股市具有投资价值     

我国的M1/M2(1978-2002):长期趋势、水平与周期波动

本对我国1978—2002年的M1／M2的长期趋势、水平和周期波动进行了研究，结果表明1978—1995年，中国的M1／M2呈急剧下降的态势，但是从1996至今则基本保持平稳。另外从国别比较来看，我国属于M1／M2比较高的国家(地区)之一，这表明我国的居民和企业由于支付制度、取款成本、规避税收等原因比美、日等国家的经济主体对M1的需求高很多。除开长期走势之外，中国的M1／M2还伴随着经济活动呈周期性的波动，实证分析结果表明1996年前的经济增长率是M1／M2周期波动的Granger原因，但1996年以后则必须由名义利率、通货膨胀率和股票市场交易量的变动才能说明M1／M2的波动。     

序列相关的微观结构噪声估计

基于股票有效价格计算的已实现波动率(Realized Variance)可作为股票收益波动率的估计,且在一定条件下,这一估计是无偏的和一致的。然而实际观测到的价格由于受到市场微观结构导致的噪声的干扰,与有效价格并不一致。因此,在高频数据环境下必须考虑如何降低噪声干扰。本文基于Hansen和Lunde给出的在噪声序列存在相关性假设下的一种关于RV的无偏估计,进一步推导出在此情形下估计噪声方差的方法。我们的估计挖掘了不同频率下的股票交易高频数据所反映出的信息,利用传统的在噪声影响下的有偏RV估计与Hansen和Lunde的无偏RV估计之间的差估计噪声。同时,本文也给出了在实践中如何确定这些频率的方法。     

信用风险水平与宏观经济变量的实证研究——基于中国、美国、日本部分银行的比较分析

基于1999～2007年中国、美国和日本部分银行的不良贷款率数据,本文对影响银行信用风险的宏观经济因素进行了实证研究和比较分析。结果表明:(1)中国的银行信用风险水平与失业率呈现显著的负相关关系;(2)表面上美国的银行信用风险水平极低,而且不受宏观经济变量波动的影响,但是实际上其风险被金融衍生工具隐藏并积累起来;(3)日本的银行信用风险水平与CPI呈现显著的负相关关系。最后本文提出了几点建议。