什么决定了企业的最佳规模?——关于企业规模的研究述评

企业规模问题是企业理论中的焦点问题,通过从市场范围、生产要素、交易费用、产权、激励成本和信息成本等六个方面综合考察决定企业规模的因素以及相应的实证研究结果,指出了关于企业规模的企业理论对企业并购的理论启示和现实意义,并展望了今后的研究前景。     

Are corrupt acts contagious?: Evidence from the United States

This paper adds to the literature by shedding new light on the causes of corruption. Specifically, we provide evidence on the extent to which corruption might be contagious. In other words, what is the extent to which a demonstration effect is at play at inducing corrupt acts? Using state-level U.S. data over the 1995–2004 period, the results show that the effect of neighboring corruption is positive and statistically significant in all cases, implying that corruption does appear to be contagious. Specifically, a 10% increase in corruption in neighboring states appears to increase corruption in a state by about 4–11%. Of the different types of government activity, the size of defense and non-defense federal sectors in a state seem to have opposite effects on corruption, with the former contributing to corruption and the latter serving as a deterrent. The size of the state and local governments does not seem to be relevant. Of the variables controlling for detection and punishment of corrupt individuals, greater corrections employment reduces corruption, while greater judicial employment seems to increase corruption. Changes in the police force do not seem to have a statistically significant impact. These findings generally hold when we control for the disproportionate effects of the Washington, DC area and when a pooled data set is estimated. Contagion effects are also found for other crimes. Policy implications are discussed.     

会计师事务所规模扩张与审计市场集中度背离的探讨

提高审计市场集中度有助于提高审计独立性 ,而规模扩张无疑是提高审计市场集中度的最直接方法 ,通过对市场选择下事务所规模化历程的分析 ,指出规模扩张有其内生性 ,我国事务所合并是政府选择的结果 ,单纯的政府推动并不能提高市场集中度     

On the sample characterization criterion for normal distributions

Conventionally, it was shown that the underlying distribution is normal if and only if the sample mean and sample variance from a random sample are independent. This paper focusses on the normal population characterization theorem by showing that, if the joint distribution of a skew normal sample follows certain multivariate skew normal distribution, the sample mean and sample variance are still independent.     

Sample Size Calculation and Blinded Sample Size Recalculation in Clinical Trials Where the Treatment Effect is Measured by the Relative Risk

In clinical trials with binary endpoints, the required sample size does not depend only on the specified type I error rate, the desired power and the treatment effect but also on the overall event rate which, however, is usually uncertain. The internal pilot study design has been proposed to overcome this difficulty. Here, nuisance parameters required for sample size calculation are re-estimated during the ongoing trial and the sample size is recalculated accordingly. We performed extensive simulation studies to investigate the characteristics of the internal pilot study design for two-group superiority trials where the treatment effect is captured by the relative risk. As the performance of the sample size recalculation procedure crucially depends on the accuracy of the applied sample size formula, we firstly explored the precision of three approximate sample size formulae proposed in the literature for this situation. It turned out that the unequal variance asymptotic normal formula outperforms the other two, especially in case of unbalanced sample size allocation. Using this formula for sample size recalculation in the internal pilot study design assures that the desired power is achieved even if the overall rate is mis-specified in the planning phase. The maximum inflation of the type I error rate observed for the internal pilot study design is small and lies below the maximum excess that occurred for the fixed sample size design.     

Three-stage designs for monitoring clinical trials

Optimal three-stage designs with equal sample sizes at each stage are presented and compared to fixed sample designs, fully sequential designs, designs restricted to use the fixed sample critical value at the final stage, and to modifications of other group sequential designs previously proposed in the literature. Typically, the greatest savings realized with interim analyses are obtained by the first interim look. More than 50% of the savings possible with a fully sequential design can be realized with a simple two-stage design. Three-stage designs can realize as much as 75% of the possible savings. Without much loss in efficiency, the designs can be modified so that the critical value at the final stage equals the usual fixed sample value while maintaining the overall level of significance, alleviating some potential confusion should a final stage be necessary. Some common group sequential designs, modified to allow early acceptance of the null hypothesis, are shown to be nearly optimal in some settings while performing poorly in others. An example is given to illustrate the use of several three-stage plans in the design of clinical trials.     

中韩企业规模比较分析

中韩两国企业规模相比，中国企业平均规模太小，迅速扩大规模，获取规模效益是中国企业应解决好的一个问题。韩国企业规模较大，为韩国的经济发展作出了贡献，虽然目前的金融危机，给一些大企业造成困难，同时大企业的经营不善又加重了金融危机，但规模大并不是其中的主要原因，我们应正确借鉴韩国这方面的经验和教训。     

Weighted bivariate logarithmic series distributions

In this paper, we are interested in the weighted distributions of a bivariate three parameter logarithmic series distribution studied by Kocherlakota and Kocherlakota (1990). The weighted versions of the model are derived with weight W(x,y) = x^[r] y^[s]. Explicit expressions for the probability mass function and probability generating functions are derived in the case r = s = l. The marginal and conditional distributions are derived in the general case. The maximum likelihood estimation of the parameters, in both two parameter and three parameter cases, is studied. A procedure for computer generation of bivariate data from a discrete distribution is described. This enables us to present two examples, in order to illustrate the methods developed, for finding the maximum likelihood estimates.     

The Role of Organizational Size and Industry in Job Quality and Work-Family Relationships

In this study we update analyses of the 1977 QES (Zipp, 1991) using data from the 1997 National Study of the Changing Workforce. We use hierarchical linear modeling procedures to partition the variance in a wide variety of indicators of workers' experiences. Most variation was associated with the individual level of analysis, but significant and nontrivial variation also was associated with the organizational and industrial levels. Although workers in smaller organizations reported lower earnings, fewer benefits, and less education than their counterparts in larger organizations, they also reported experiencing less discrimination, better fit between their actual and desired work hours, more supportive work environments and loyalty to their employers, less burnout or interference between work and family, and shorter commute times.     

Rank tests in the two-sample scale problem with unequal and unknown locations

The two-sample scale problem is studied in the case of unequal and unknown location parameters. The method proposed is based on the idea of Moses (1963) and it is distribution-free. The two samples are separated into random subgroups of the same sizek. It is proposed to choosek=4 and to apply the Wilconxon test or the Savage test to the ranges or sample variances of the subgroups. The asymptotic power functions of the tests are compared. For small and moderate sample sizes simulations are carried out. Relations to some other procedures, especially to the method of Compagnone and Denker (1996) are briefly discussed.