Measuring inter-racial friendships

Different methods of measuring inter-racial contacts produce large differences in the level of the same. Experiments conducted on the 1998 General Social Survey indicate that estimates of how many people have inter-racial friends are much higher when a direct question is asked, intermediate when a three-step procedure is used, and the least when a name-generator, network approach is used. Cognitive and social desirability reasons for these effects are discussed.     

Editorial: Women and work

Abstract

When compared to day workers, night-shift workers report that they eat fewer meals, have poorer appetites, are less satisfied with their eating habits, and eat at different times of the day. When demographic variables are held constant, there do not appear to be any significant differences between experienced day and night-shift workers in caffeine or alcohol consumption. Exceptions to and variations in these findings are probably due to the background influences of social and cultural variables. Eating and drinking behaviours do effect human performance and mood, but little relevant data have been gathered from experienced night-shift workers. There are no shiftworker data evaluating the effectiveness of the special diets or dietary recommendations that have been proposed for use by night-shift workers. Thus, attempts to manipulate night-shift worker eating and drinking habits require experimental test.     

Coming Out and Coming Home

This paper draws on the testimonies of British disabled lesbians and gay men about their experience of coming out as gay, and coming out as disabled. They reflect on the different aspects of their identity, and the interrelation of their sexuality and their disability. The respondents share their experiences of exclusion and marginality in both the disability and gay communities, and discuss where they feel most at home as disabled lesbians and gays.     

A simple way to obtain the spectral decomposition of variance components models for balanced data

By means of an example it is shown how eigenvalues and eigenvectors of variance components models can be obtained straightforwardly when balanced data are available. Simple asymptotically efficient estimators of the variance components are presented.     

Who We Are Affects How We Do: The Financial Benefits of Organizational Identification

One ultimate test of the material value of identification in an organizational context is whether it relates to productivity. In this rare study of a business team in a global consumer goods company, we demonstrate a sales benefit of organizational identification when correcting for systematic between‐unit differences in sales. Findings also question the theoretical and practical meaning of ‘proximity’ in accounting for salience variations in identification – the best predictor of sales was the degree of identification with the superordinate business unit. Findings shed light on the scientific as well as managerial and business utility of the organizational identity concept.     

Bayesian inference for dynamic social network data

We consider a continuous-time model for the evolution of social networks. A social network is here conceived as a (di-) graph on a set of vertices, representing actors, and the changes of interest are creation and disappearance over time of (arcs) edges in the graph. Hence we model a collection of random edge indicators that are not, in general, independent. We explicitly model the interdependencies between edge indicators that arise from interaction between social entities. A Markov chain is defined in terms of an embedded chain with holding times and transition probabilities. Data are observed at fixed points in time and hence we are not able to observe the embedded chain directly. Introducing a prior distribution for the parameters we may implement an MCMC algorithm for exploring the posterior distribution of the parameters by simulating the evolution of the embedded process between observations.     

A Test to Detect Within-family Infectivity when the Whole Epidemic Process is Observed

An epidemic model for the spread of an infectious disease in a population of families is considered. The score test of the hypothesis that there is no higher infectivity between family members is constructed under the assumption that the epidemic process is observed continuously up to some time t . The score process is a martingale as a function of t and by letting the number of families tend to infinity, a central limit theorem for the process can be proved. The central limit theorem not only justifies a normal approximation of the test statistic—it also suggests a smaller variance estimator than expected.     

Bayesian point null hypothesis testing via the posterior likelihood ratio

This paper gives an exposition of the use of the posterior likelihood ratio for testing point null hypotheses in a fully Bayesian framework. Connections between the frequentist P-value and the posterior distribution of the likelihood ratio are used to interpret and calibrate P-values in a Bayesian context, and examples are given to show the use of simple posterior simulation methods to provide Bayesian tests of common hypotheses.