Two separate effects of variance heterogeneity on the validity and power of significance tests of location

Heterogeneity of variances of treatment groups influences the validity and power of significance tests of location in two distinct ways. First, if sample sizes are unequal, the Type I error rate and power are depressed if a larger variance is associated with a larger sample size, and elevated if a larger variance is associated with a smaller sample size. This well-established effect, which occurs in t and F tests, and to a lesser degree in nonparametric rank tests, results from unequal contributions of pooled estimates of error variance in the computation of test statistics. It is observed in samples from normal distributions, as well as non-normal distributions of various shapes. Second, transformation of scores from skewed distributions with unequal variances to ranks produces differences in the means of the ranks assigned to the respective groups, even if the means of the initial groups are equal, and a subsequent inflation of Type I error rates and power. This effect occurs for all sample sizes, equal and unequal. For the t test, the discrepancy diminishes, and for the Wilcoxon–Mann–Whitney test, it becomes larger, as sample size increases. The Welch separate-variance t test overcomes the first effect but not the second. Because of interaction of these separate effects, the validity and power of both parametric and nonparametric tests performed on samples of any size from unknown distributions with possibly unequal variances can be distorted in unpredictable ways.     

区域化网上卖场的实施探讨

目前我国的零售业发展处于经济效益欠佳、发展秩序混乱的现状之中。本文通过对国内零售业及B2C电子商务模式进行研究,针对目前国内零售企业发展的困境,提出区域化网上卖场发展的方案,并深入分析了区域化网上卖场实施的必要性、可行性及策略。     

The effect of education,income inequality and merit on inequality acceptance

A large number of observational and experimental studies have explored the determinants of individual preferences for redistribution. In general, inequalities are more likely to be accepted by people of higher socioeconomic status, in richer societies and when inequalities are perceived as justifiable owing to differences in productivity. Almås et al. (2020) show that in a relatively unequal society (the United States), the highly educated accept inequality significantly more than the less educated, whereas, in a relatively equal society (Norway), the less educated accept inequality more, but not significantly more, than the highly educated. Here, we replicate this finding using data from experiments conducted in four locations across three countries all distinct from the ones studied by Almås et al. However, a closer look at the data indicates that the origin of the interaction effect varies depending on which societies one compares. Data for Norway and the United States indicate that meritocratic values among the highly educated are less prevalent in more equal societies and that this is the driver of the triple interaction effect. In contrast, in our data the interaction effects have multiple drivers.     

Strategic evaluation criteria to assess competitiveness of the service industry in Taiwan

This study uses industrial upgrading (I), export development (E), and investment promotion (K), or collectively, the IEK model to identify critical indicators to asses competitiveness of the service industry in Taiwan. The proposed development and evaluation model for the service industry uses the DEMATEL (decision-making trial and evaluation laboratory) method to construct an influential relationship between the dimensions and criteria; a DEMATEL-based analytic network process (DANP) to obtain influential weights; and a modified Vlšekriterijumska Optimizacija I Kompromisno Resenje (m-VIKOR) method to assess gaps in industry development performance. It illuminates current industry demands and helps to improve service firms’ operations through fewer developmental gaps and stronger policy and strategy. Further, an influential network relationship map (INRM) and influential weights can unravel the complex assessment system and prioritise industry improvements. The results demonstrate that upgrades must occur first to the industry, then to promoting of investments, and lastly, in developing exports. Finally, the practical implications for managing service firms have been discussed.     

Special theme introduction: methodological cosmopolitanism across the socio‐cultural sciences

The cosmopolitan sociology of Ulrich Beck has been widely recognized as making vital contributions to crosscutting conversations on globalization and transnational studies, including these debates that are being played out on the pages of Global Networks. Beck's impassioned critique of ‘methodological nationalism’ in his own discipline of sociology, in particular, has often served as a springboard for programmatic calls to attend more closely to transnational actors, issues, and processes. However, beyond the occasional acknowledgement, comparatively less attention has been paid so far to the potentialities, specificities, and practicalities of Beck's affirmative alternative vision for the socio‐cultural sciences, that of ‘methodological cosmopolitanism’. Building on and extending out from research experiences obtained in Beck's East Asia and Europe‐focused Cosmopolitan Climate Change (Cosmo‐Climate) project, this special theme brings together experts from across a range of socio‐cultural research fields to discuss and critically interrogate the challenges and capacities of doing methodological cosmopolitanism.     

A comparison of Monte Carlo methods for computing marginal likelihoods of item response theory models

Nowadays, Bayesian methods are routinely used for estimating parameters of item response theory (IRT) models. However, the marginal likelihoods are still rarely used for comparing IRT models due to their complexity and a relatively high dimension of the model parameters. In this paper, we review Monte Carlo (MC) methods developed in the literature in recent years and provide a detailed development of how these methods are applied to the IRT models. In particular, we focus on the “best possible” implementation of these MC methods for the IRT models. These MC methods are used to compute the marginal likelihoods under the one-parameter IRT model with the logistic link (1PL model) and the two-parameter logistic IRT model (2PL model) for a real English Examination dataset. We further use the widely applicable information criterion (WAIC) and deviance information criterion (DIC) to compare the 1PL model and the 2PL model. The 2PL model is favored by all of these three Bayesian model comparison criteria for the English Examination data.     

Competition-induced punishment of winners and losers: Who is the target?

We elicit punishment after competition. Our experiment creates a setting in which winners and losers are assigned in a pairwise speed-based calculation task. As in Abbink and Sadrieh’s (2009) joy-of-destruction game punishment is executed by burning parts of another participant’s endowment. We manipulate the target of punishment to investigate whether it is driven by discrimination of the direct opponent, the outgroup or by joy of destruction. Furthermore, we analyze the role that the clarity of victory or defeat plays for punishment after competition. Our findings suggest that losers face punishment from particularly dominant winners and—to a lesser degree—from particularly frustrated losers. Winners face undifferentiated punishment from all sides. Our results have implications for the prevention of destructive behavior within organizations which use competitions in order to induce effort.     

Efficiency of financial market intermediation in Kenya: A comparative analysis

Wide interest margins as witnessed in Kenya are a sign of a repressed and inefficient financial sector. This paper carries out a cross-country analysis of the determinants of financial market efficiency using panel cointegration with a view to recommending policy options for improving the efficiency of the financial sector intermediation process in Kenya. The study finds that the major contributors to the differences in financial sector inefficiency in Kenya compared to the other countries in the study are high bank operating costs, default risk and financial market structure. The study recommends, among other measures, that the government through the Central Bank need to collaborate with the commercial banks and establish a working credit reference bureau to enable easy identification of credit worthy customers in order to reduce default risk; there is also need by the central bank to license more new banks to increase competition and reduce bank concentration. The study also recommends increased use of technology including phone-banking and e-banking to reduce operation costs of the banks. The paper concludes that contrary to the findings from other cross-country analysis, the factors that lead to financial market in/efficiency varies from one country to the other.     

C+C合建站中脉冲雷达新工作模式精度分析

介绍了雷达测量精度相关原理、测量误差的计算方法以及C+C合建站的基本工作原理,分析了合建站中单脉冲测量雷达系统与统一测控系统角度测量误差分量的异同,并计算了C+C合建站中脉冲雷达新工作模式的测量误差,通过处理实测数据验证脉冲雷达新工作模式的测量精度.     

COMMON FEATURES IN TIME SERIES WITH BOTH DETERMINISTIC AND STOCHASTIC SEASONALITY

This paper extends the notions of common cycles and common seasonal features to time series having deterministic and stochastic seasonality at different frequencies. The conditions under which quarterly time series with these characteristics have common features are investigated, various representations are presented and statistical inference is discussed. Finally, the analysis is applied to study comovements between different components of consumption and income using UK data.