A simple procedure for the selection of significant effects

Summary.  Given a large number of test statistics, a small proportion of which represent departures from the relevant null hypothesis, a simple rule is given for choosing those statistics that are indicative of departure. It is based on fitting by moments a mixture model to the set of test statistics and then deriving an estimated likelihood ratio. Simulation suggests that the procedure has good properties when the departure from an overall null hypothesis is not too small.     

Robustness of testing the equality of two slopes in simple linear structural relationships

The usual test of the equality of two slopes in a simple structural relation-ship is the test formed from the normal approximation using the Fisher information matrix, assuming two explanatory variables are independent. This paper examines the robustness if the explanatory variables are, in fact, dependent. A more efficient estimator is derived for a matched pair situation.     

Portmanteau test for conditional heteroscedasticity, using ranks of squared residuals

Squared residual autocorrelations have been found useful in detecting departures from linearity in time series models. This is especially the case with data exhibiting heterogeneity in variances. A rank test is proposed which is much more robust than its parametric counterpart.     

Japanese marketing strategies in the United Kingdom

This article is based on a study which examined hypotheses about Japanese marketing using a matched sample of British companies and their major Japanese competitors. Japanese subsidiaries in Britain were shown to be much more marketing-oriented, more responsive to strategic opportunities, and more single-minded in their pursuit of market share. Organizationally, there were few differences between the two groups. The Japanese subsidiaries, however, were more inclined to use product or market-based divisions and continuous, informal planning and control procedures. The result is that managerial focus and responsibility are centred upon overall product-market rather than financial or production performance, with continuous feedback facilitating rapid adaptation and implementation of marketing plans and strategy.     

Gender disparity in the C-suite: Do male and female CEOs differ in how they reached the top?

Through a comparison of the life and career trajectories of thirty male and thirty female CEOs of large organizations, this study offers insights into the genesis of gender disparity in corporate leadership positions, discusses the implications for leadership development, and puts forward a model explaining the disparity in CEO roles. We found gendered patterns in the accumulation of career relevant experiences stretching back to birth into working lives that created significant and cumulative limitations upon the ability of women to access CEO roles and the types of CEO appointments available to them. Limited access to career relevant experiences in childhood, adolescence and in organizations lead to on-going limitations in capital accumulation throughout women's careers. Implications of our findings for both theory and practice are discussed.     

Methods to assess measurement error in questionnaires of sedentary behavior

Sedentary behavior has already been associated with mortality, cardiovascular disease, and cancer. Questionnaires are an affordable tool for measuring sedentary behavior in large epidemiological studies. Here, we introduce and evaluate two statistical methods for quantifying measurement error in questionnaires. Accurate estimates are needed for assessing questionnaire quality. The two methods would be applied to validation studies that measure a sedentary behavior by both questionnaire and accelerometer on multiple days. The first method fits a reduced model by assuming the accelerometer is without error, while the second method fits a more complete model that allows both measures to have error. Because accelerometers tend to be highly accurate, we show that ignoring the accelerometer's measurement error, can result in more accurate estimates of measurement error in some scenarios. In this article, we derive asymptotic approximations for the mean-squared error of the estimated parameters from both methods, evaluate their dependence on study design and behavior characteristics, and offer an R package so investigators can make an informed choice between the two methods. We demonstrate the difference between the two methods in a recent validation study comparing previous day recalls to an accelerometer-based ActivPal.     

"Little" and "Big" Pictures in Our Heads: Race, Local Context, and Innumeracy About Racial Groups in the United States

Americans do not know what percentage of the nation's residentsare whites, blacks, Hispanics, Asians, and American Indians.Using the 2000 General Social Survey, I find that respondentsof all races underestimate the percentages of whites and overestimatethe percentages of racial/ethnic minority groups and multiracialAmericans in the United States; however, they perceive theirlocal communities quite differently. As a first step towardunderstanding this discrepancy, I test whether individuals’local surroundings serve as a source of information for theirpictures of the United States. I examine the relationship between"objective" data and respondents’ subjective perceptionsof where they live, and compare their respective effects onAmericans’ perceptions of the nation. Multivariate multilevelanalyses show that respondents’ perceptions of differentracial group sizes in their communities are the strongest predictorsof innumeracy at the national level, while "objective" racialcontext measured at the local level has less of an effect. Thesefindings have important implications for research on racialcontext, which assumes that census numbers for respondents’locales are good proxies for their perceptions of the size ofracial/ethnic groups in their communities. Furthermore, thesefindings suggest that scholars need to start thinking aboutwhy whites and non-whites have similar "big pictures" of thenation, why their "little pictures" vary a great deal, and whythe motivations for over- and underestimation may differ byracial/ethnic group.