Influence diagnostics in Gaussian spatial linear models

Spatial linear models have been applied in numerous fields such as agriculture, geoscience and environmental sciences, among many others. Spatial dependence structure modelling, using a geostatistical approach, is an indispensable tool to estimate the parameters that define this structure. However, this estimation may be greatly affected by the presence of atypical observations in the sampled data. The purpose of this paper is to use diagnostic techniques to assess the sensitivity of the maximum-likelihood estimators, covariance functions and linear predictor to small perturbations in the data and/or the spatial linear model assumptions. The methodology is illustrated with two real data sets. The results allowed us to conclude that the presence of atypical values in the sample data have a strong influence on thematic maps, changing the spatial dependence structure.     

The association of smoking with drinking pattern may provide opportunities to reduce smoking among students

There is evidence that smoking and alcohol consumption are paired behaviours among university students, but we know little about how New Zealand students engage in these behaviours. We estimated prevalence of daily and occasional smoking among university students, and associations of smoking with drinking patterns, demographics and smokefree policies of the university. This research was conducted with 2822 university students, aged 17–25, from five New Zealand universities who participated in an online health survey in 2013. Fourteen percent reported they currently smoke occasionally, and 3% reported smoking on a daily basis. Increasing age, living situation, drinking more often, and drinking more alcohol during drinking occasions were all associated with greater levels of smoking. Understanding patterns of smoking in relation to alcohol consumption may help efforts to further reduce smoking prevalence. Specifically, policy makers should consider approaches that de-couple tobacco and alcohol consumption, such as expanding the smokefree perimeter of bars and disallowing the sale of tobacco at premises licensed to sell alcohol.     

Occupational Segregation and the Female–Male Wage Differentials: Evidence for Spain

Using matched employer–employee data from the Spanish labour market in 2010, we analyse the effects of industrial, establishment and occupational segregation on the gender wage differential, disaggregating the latter contribution by different groups of workers belonging to different occupational areas and responsibility levels. These workers are employed in 61 occupations within 26,492 establishments in 51 different industries. Since the matched employer–employee data exhibit a particular type of grouped structure, which contrasts the statistical properties of such data with the random sample case, we estimate the effects of each type of gender segregation on the wage gap using a robust specification. We find that the major part of the contribution of gender segregation is not explained by differences in the observable characteristics. Furthermore, the estimations show that the educational female advantage has helped to narrow the gender wage gap caused by occupational segregation within each establishment only for those groups of workers with the lowest educational requirements.     

Research records and the resolution of misconduct allegations at research universities

Accurate record keeping is an important part of the responsible conduct of research. However, there is very little empirical research on scientific record keeping. No one knows the incidence of serious problems with research records, the types of problems that occur, nor their consequences. In this study, we examined the role of research records in the resolution of misconduct allegations as a useful barometer for the incidence and types of problems that occur with records. We interviewed Research Integrity Officers (RIOs) at 90 major research universities and conducted focus groups with active research faculty. RIOs reported problems with research records in 38% of the 553 investigations they conducted. Severe problems with research records often prevented completion of investigations while problems that are more typical lengthened them by 2 to 3 weeks. Five types of poor record keeping practices accounted for 75 % of the problems with incomplete/inadequate records being the most common (30%). The focus groups concurred with the findings from the interviews with RIOs, stressed the importance of the research group leader in setting and maintaining record practices, and offered additional insights. While university officials and faculty members have suspected for many years that there are serious problems with research record keeping, our study provides empirical evidence for this belief. By documenting some of the problems with record keeping in university-based research, the results of our study provide information that will be useful for policy development at academic institutions.     

Estimating Intraclass Correlation Coefficient and Identifying Influential Observations Under One-Way Random Effects Model

In this paper we consider the estimation of intraclass correlation coefficient and identification of influential observations under one-way random effects model. We introduce an approach to correct negative estimation values induced by the method of moments estimator, and provide an interval estimation for intraclass correlation coefficient. We present the diagnostic tools to identify influential observations through the uncorrected estimate of intraclass correlation coefficient. A simulation study is conducted to investigate the performance of our procedure for identifying influential observations. We also apply the method on a real data of repeated blood pressure measurements.     

Deploying for Deliverance: The Digital Divide in Municipal Wireless Networks

Abstract

The use of information technology (IT) is growing; access and use differ among those from different races, ethnicities, income and education levels, jobs, ages, and genders. Although some argue that broadband technology could be the platform for universal access, the benefits are still debatable for municipalities providing access. The authors discuss how public officials have decided to lead, support, and usher in an era of rapid IT development through wireless broadband networks to address digital divide concerns, and how these claims may meet—or fail to meet—expectations. The purpose of this paper is twofold: (1) to propose a fruitful investigative overview of U.S. cities claiming that a municipal wireless network will bridge the “digital divide”; and (2) to employ discourse analysis to examine the digital divide language 24 municipal wireless networks (MWNs) use.     

Phi-Divergence Statistics for Testing Linear Hypotheses in Logistic Regression Models

In this paper we introduce and study two new families of statistics for the problem of testing linear combinations of the parameters in logistic regression models. These families are based on the phi-divergence measures. One of them includes the classical likelihood ratio statistic and the other the classical Pearson's statistic for this problem. It is interesting to note that the vector of unknown parameters, in the two new families of phi-divergence statistics considered in this paper, is estimated using the minimum phi-divergence estimator instead of the maximum likelihood estimator. Minimum phi-divergence estimators are a natural extension of the maximum likelihood estimator.     

The dynamic,complex and diverse living and care arrangements of young New Zealanders: implications for policy

The living arrangements of young people in New Zealand are diverse and often complex. In this article we report the range of care and living arrangements of 209 15-year-old New Zealanders, 47 of whom identified as Māori. These young people were participants in the second generation of a cohort study. Data were collected from their parents via a life history calendar and analysed for variety and consistency of care arrangements, household membership and transitions. Few participants had a consistent pattern of parental care arrangements and most had experienced multiple changes in household composition and frequent changes of address. We conclude that the whānau/family lives of many young New Zealanders are complex and dynamic. These observations contrast with the conventional notions of family life that form the basis for New Zealand’s family policies. We argue that social policies and services impacting on young people need to reflect the lived reality of young people if they are to meet young people’s needs.     

The Impact on Inequality of Raising the Minimum Wage: Gap‐narrowing and Reranking Effects

Raising the minimum wage may reduce inequality by increasing the wages of low‐skill workers, but it may also increase inequality due to negative impacts on employment that produce wage losses. Using previous estimates of the elasticities of wages and employment to changes in the minimum wage in Colombia and Brazil, we show that the net impact on inequality of increasing the minimum wage may depend on the distributional weights used for inequality measurement. The results are obtained by decomposing the Gini index into reranking and gap‐narrowing effects. Inequality‐increasing reranking effects, which are associated with job losses, may dominate inequality‐decreasing gap‐narrowing effects, which are associated with wage gains, when high weights are placed on workers with low earnings. For standard distributional weights, however, the likely net impact is a reduction in wage inequality.     

Legacies of empire?

Using methods and themes from Charles Tilly’s work, this paper presents a number of propositions related to empire-to-state transformation. We argue that variations in national state development from imperial metropole origins can be explained, at least in part, by variations in imperial administration, finance, development, identity, and inequality. Capacity is a critical determinant of the results of state transformation, while decisions about finance and investment are both economic and political. Identity and inequality are inextricably linked to empire, and our exploration of these concepts demonstrates that they are the outcomes of variable processes linked to concrete, if inadvertent, lines of imperial decisions.