The beta-binomial convolution model for 2×2 tables with missing cell counts

This paper considers the beta-binomial convolution model for the analysis of 2×2 tables with missing cell counts. We discuss maximum-likelihood (ML) parameter estimation using the expectation–maximization algorithm and study information loss relative to complete data estimators. We also examine bias of the ML estimators of the beta-binomial convolution. The results are illustrated by two example applications.     

Information loss for 2 × 2 tables with missing cell counts: binomial case

We formulate likelihood-based ecological inference for 2 × 2 tables with missing cell counts as an incomplete data problem and study Fisher information loss by comparing estimation from complete and incomplete data. In so doing, we consider maximum-likelihood (ML) estimators of probabilities governed by two independent binomial distributions and obtain simplified expressions for their covariance. These expressions reflect well the additional uncertainty arising from the unobserved data compared to complete data tables. We also discuss an approximation to the expected conditional variance of the unobserved entries and ML parameter bias correction. An empirical example is used to demonstrate the results.     

Unconditional tests for association in 2 × 2 contingency tables in the total sum fixed design

The asymptotic approach and Fisher's exact approach have often been used for testing the association between two dichotomous variables. The asymptotic approach may be appropriate to use in large samples but is often criticized for being associated with unacceptable high actual type I error rates for small to medium sample sizes. Fisher's exact approach suffers from conservative type I error rates and low power. For these reasons, a number of exact unconditional approaches have been proposed, which have been seen to be generally more powerful than exact conditional counterparts. We consider the traditional unconditional approach based on maximization and compare it to our presented approach, which is based on estimation and maximization. We extend the unconditional approach based on estimation and maximization to designs with the total sum fixed. The procedures based on the Pearson chi‐square, Yates's corrected, and likelihood ratio test statistics are evaluated with regard to actual type I error rates and powers. A real example is used to illustrate the various testing procedures. The unconditional approach based on estimation and maximization performs well, having an actual level much closer to the nominal level. The Pearson chi‐square and likelihood ratio test statistics work well with this efficient unconditional approach. This approach is generally more powerful than the other p‐value calculation methods in the scenarios considered.     

Bayesian estimation of log odds ratios from R × C and 2 × 2 × K contingency tables

In this paper, Bayesian estimation of log odds ratios over R × C and 2 × 2 × K contingency tables is considered, which is practically reasonable in the presence of prior information. Likelihood functions for log odds ratios are derived for each table structure. A prior specification strategy is proposed. Posterior inferences are drawn using Gibbs sampling and Metropolis–Hastings algorithm. Two numerical examples are given to illustrate the matters argued.     

Stratified studies about risk ratios in 2 × 2 tables with structural zero

Incomplete correlated 2 × 2 tables are common in some infectious disease studies and two‐step treatment studies in which one of the comparative measures of interest is the risk ratio (RR). This paper investigates the two‐stage tests of whether K RRs are homogeneous and whether the common RR equals a freewill constant. On the assumption that K RRs are equal, this paper proposes four asymptotic test statistics: the Wald‐type, the logarithmic‐transformation‐based, the score‐type and the likelihood ratio statistics to test whether the common RR equals a prespecified value. Sample size formulae based on hypothesis testing method and confidence interval method are proposed in the second stage of test. Simulation results show that sample sizes based on the score‐type test and the logarithmic‐transformation‐based test are more accurate to achieve the predesigned power than those based on the Wald‐type test. The score‐type test performs best of the four tests in terms of type I error rate. A real example is used to illustrate the proposed methods.     

Extensions of linear diagonal-parameter symmetry and quasi-symmetry models for cumulative probabilities in square contingency tables

For square contingency tables with ordered categories, CAUSSINUS [Annales de la Faculté des Sciences de l'Université de Toulouse (1965) Vol. 29, pp. 77–182] and AGRESTI [Statistics and Probability Letters (1983) Vol. 1, pp. 313–316] considered the quasi-symmetry and the linear diagonal-parameter symmetry models, respectively, which have multiplicative forms for cell probabilities. This paper proposes two kinds of models that have the similar multiplicative forms for cumulative probabilities that an observation will fall in row (column) category i or below and column (row) category j (> i ) or above. The endometrial cancer data are analyzed using these models.     

Asymptotic comparison at optimal levels of reduced‐bias extreme value index estimators

In this article we are interested in the asymptotic comparison, at optimal levels, of a set of semi‐parametric reduced‐bias extreme value (EV) index estimators, valid for a wide class of heavy‐tailed models, underlying the available data. Again, as in the classical case, there is not any estimator that can always dominate the alternatives, but interesting clear‐cut patterns are found. Consequently, and in practice, a suitable choice of a set of EV index estimators will jointly enable us to better estimate the EV index γ, the primary parameter of extreme events.     

On a 2 × 2 factorial design where the use of randomized response is one of the factors

This paper discusses a survey where some respondents were asked sensitive questions directly and others were asked the same questions using randomized response. The use of randomized response was a factor in a 2 × 2 factorial design and dice were used to perform the randomization. First, the paper shows that the perturbation due to the dice can be described using the concept of misclassification and known conditional misclassification probabilities. Second, the paper formulates the likelihood for loglinear models and shows that latent class software can be used to analyse the data. An example including a power analysis is discussed.     

B2C情境下感知风险的演变过程以及降低风险策略研究

感知风险是制约消费者网上购物的主要因素。文中选取在校大学生为样本,研究网络情境下消费者感知风险在购物不同阶段的体现,利用计量经济学中统计建模的方式探讨个人因素、购物经历等控制变量在各个阶段对感知风险是否存在影响;通过演变图得出这些因素对感知风险的不同影响。研究发现感知风险程度随着收集信息、评价方案以及购后行为三个阶段的递进而持续递增,且各因素对产品存在不同的影响。最后,基于感知风险的演变过程提出相关的营销策略。     

Shaping buyer–supplier relationships in manufacturing contexts: Design and test of a contingency model

Although the idea that buyer–supplier partnerships can yield considerable benefits to firms is largely diffused among researchers and practitioners, the approach adopted in this paper is that no “one best way” exists in buyer–supplier relationships, but rather a “best way” for each specific exchange context. Hence, this paper proposes a contingency model for shaping and managing buyer–supplier relationships in manufacturing contexts. In order to test the model, an empirical study was performed on a sample of 45 buyer–supplier relationships within the Italian white goods industry. A three-dimensional performance indicator was computed to compare supplier performance achieved within relations matching the model's suggestions with those set differently. The results strongly suggest that suppliers involved in relationships set accordingly to the contingency model are likely to enjoy superior performance.     

Performance of empirical Bayes estimators of random coefficients in multilevel analysis: Some results for the random intercept-only model

For a multilevel model with two levels and only a random intercept, the quality of different estimators of the random intercept is examined. Analytical results are given for the marginal model interpretation where negative estimates of the variance components are allowed for. Except for four or five level-2 units, the Empirical Bayes Estimator (EBE) has a lower average Bayes risk than the Ordinary Least Squares Estimator (OLSE). The EBEs based on restricted maximum likelihood (REML) estimators of the variance components have a lower Bayes risk than the EBEs based on maximum likelihood (ML) estimators. For the hierarchical model interpretation, where estimates of the variance components are restricted being positive, Monte Carlo simulations were done. In this case the EBE has a lower average Bayes risk than the OLSE, also for four or five level-2 units. For large numbers of level-1 (30) or level-2 units (100), the performances of REML-based and ML-based EBEs are comparable. For small numbers of level-1 (10) and level-2 units (25), the REML-based EBEs have a lower Bayes risk than ML-based EBEs only for high intraclass correlations (0.5).     

Comparing cross‐country estimates of Lorenz curves using a Dirichlet distribution across estimators and datasets

Chotikapanich and Griffiths (Journal of Business and Economic Statistics, 2002, 20(2), 290–295) introduced the Dirichlet distribution to the estimation of Lorenz curves. This distribution naturally accommodates the proportional nature of income share data and the dependence structure between the shares. Chotikapanich and Griffiths fit a family of five Lorenz curves to one year of Swedish and Brazilian income share data using unconstrained maximum likelihood and unconstrained nonlinear least squares. We attempt to replicate the authors' results and extend their analyses using both constrained estimation techniques and five additional years of data. We successfully replicate a majority of the authors' results and find that some of their main qualitative conclusions also hold using our constrained estimators and additional data.     

Quick consistency of quasi-maximum likelihood estimators in a multivariate poisson process

Recent results by the present author on quick consistency of quasi-maximum likelihood estimators of parameters in a multivariate Poisson process are strengthened at the cost of replacing the inverse continuity assumption with the strong uniform identifiability condition.     

Sparse estimators and the oracle property,or the return of Hodges’ estimator

We point out some pitfalls related to the concept of an oracle property as used in Fan and Li [2001. Variable selection via nonconcave penalized likelihood and its oracle properties. Journal of the American Statistical Association 96, 1348–1360; 2002. Variable selection for Cox's proportional hazards model and frailty model. Annals of Statistics 30, 74–99; 2004. New estimation and model selection procedures for semiparametric modeling in longitudinal data analysis. Journal of the American Statistical Association 99, 710–723] which are reminiscent of the well-known pitfalls related to Hodges’ estimator. The oracle property is often a consequence of sparsity of an estimator. We show that any estimator satisfying a sparsity property has maximal risk that converges to the supremum of the loss function; in particular, the maximal risk diverges to infinity whenever the loss function is unbounded. For ease of presentation the result is set in the framework of a linear regression model, but generalizes far beyond that setting. In a Monte Carlo study we also assess the extent of the problem in finite samples for the smoothly clipped absolute deviation (SCAD) estimator introduced in Fan and Li [2001. Variable selection via nonconcave penalized likelihood and its oracle properties. Journal of the American Statistical Association 96, 1348–1360]. We find that this estimator can perform rather poorly in finite samples and that its worst-case performance relative to maximum likelihood deteriorates with increasing sample size when the estimator is tuned to sparsity.     

油田钻井过程中硫化氢的监控与应急分析

硫化氢是一种毒气,在钻井过程中,如果硫化氢散出地面并泄漏,将会危及到每位员工的生命安全。文章按油田的实际运作过程对硫化氢实施监控、防护以及应急救援措施进行了分析。     

Chamberlin’s strategy of multiple working hypotheses and a relative frequency theory of market demand

The neoclassical theory of demand based on fixed indifference map hypotheses has not yet become significantly assertible in the sense of modern logic. That is because of the great difficulty encountered in empirical confirmation of its presuppositions and antecedent hypotheses, which is essential to its significant assertibility. Full confirmation of antecedent conditions is impossible with market equilibrium data alone. That puts a considerable premium on approaching any investigation in econometric demand analysis with several mutually testable hypotheses that are already well-explored and thought through. Preparation is necessary to recognize when otherwise interesting mutually testable economic hypotheses cannot be tested because the nature of the data required has not yet been adequately discerned.     

A Cross‐National Study of Fairness in Asia: How Perceptions of a Lack‐of‐Group Bias and Transparency in the Performance Evaluation System Relate to Job Satisfaction

This study explored how managers’ fairness perceptions of performance evaluation systems differ across countries and relate to their job satisfaction. Lack‐of‐group bias and transparency were the constructs used to assess fairness perceptions. The data sample consisted of 903 Asian managers from the subsidiaries of a leading multinational corporation (MNC) strategically expanding its retail markets in Japan, China, Hong Kong, Malaysia, and Thailand. Results showed that the fairness perceptions of lack‐of‐group bias and transparency concerning the common performance evaluation system varied within these Asian countries. Furthermore, those fairness perceptions were significantly related to job satisfaction among Asian managers overall, as well as in each of the five geographical subgroups with the exception of Hong Kong, where the perception of a lack‐of‐group bias was only marginally related to job satisfaction. These findings offer theoretical implications regarding organizational justice, cross‐national management, and performance evaluation, as well as practical implications for leveraging organizational justice perceptions of performance evaluation systems for the effectiveness of MNCs. © 2015 Wiley Periodicals, Inc.     

城市安全风险评价的理论与实践

从城市综合减灾的高度较为系统地探讨了城市安全建设与发展中的诸问题,特别针对城市安全及工程安全规划设计所涉及的备灾系统,研究了安全容量优化配置的理论及评价方法,同时探讨了大型工程安全风险评价的框架及思路.     

Human resource management control system and firm performance: a contingency model of corporate control

This study explores how corporate controls used by the parent company of a conglomerate affect subsidiaries' human resource management (HRM) control–performance relationship. Empirical results from 93 firms reveal that the appropriate use of HRM control systems was a contributing factor to firm performance. When a subsidiary's approach to HRM was based on behavior control, performance was lower when the parent company emphasized financial control. When a subsidiary's approach to HRM was based on output control, performance was higher when the parent company emphasized either strategic or financial control. When a subsidiary's approach to HRM was based on input control, performance was higher when the parent company emphasized strategic control.