Bootstrap techniques for proportional hazards models with censored observations

We propose a bootstrap technique for generating pseudo-samples from survival data containing censored observations. This simulation selects a survival time with replacement from the data and then assigns a covariate according to the model of proportional hazards. We also develop a constrained bootstrap technique in which every pseudo-sample has the same distribution of covariate values as does the original, observed data. We use these simulation techniques to estimate the bias and variance of regression coefficients and to approximate the significance levels of goodness-of-fit statistics for testing the assumption of the proportional hazards model.     

How Children Spend Their Time: A Sample Survey for Use in Exposure and Risk Assessments

Children are becoming an increasingly important focus for exposure and risk assessments because they are more sensitive than adults to environmental contaminants. A necessary step in measuring the extent of children's exposure and in calculating risk assessments is to document how and where children spend their time. This 1990-1991 survey of 1000 households was designed for this purpose, targeting children between 5 and 12 years of age, in six states in varied geographic regions. The behavior of children was sampled on both weekdays and weekends over all four seasons of the year using a retrospective time diary to allocate time to activities during the previous 24 h. Information was obtained on the kinds and locations of activities, the nature of the microenvironments of the locations, and the time spent in the different environments. Measures of variability in addition to mean hours per day are reported. Results of this study closely match those of earlier research on California children's activities done by the California Air Resources Board. One important finding of the survey was that 5- to 12-year-old children in all geographic regions spend most of their time indoors at home, indicating that risk assessments should focus on indoor, on-site hazards.     

Elite and upper class in philadelphia, 1975

This study examines the relationship between the Philadelphia elite and upper class in 1975. Much of this study is a historical replication of Baltzell's 1958 analysis of the Philadelphia elite and upper class in 1940. Data on the occupations, educational affiliations, club memberships, and religious affiliations of upper class and nonupper class members of the Philadelphia elite of 1975 generally are comparable to those presented by Baltzell for 1940. Yet the proportion of the elite that is upper class is smaller than in Baltzell's analysis, and holds a smaller proportion of all corporate directorships reported by the elite, including directorships in major Philadelphia banks. These latter data support the assertion that the Philadelphia upper class lost some of its influence in the decades after World War II.     

Linking Community Context to Quality of Parenting: A Study of Rural Families1

Abstract Virtually all past studies of the effect of community context on families and children have focused on large metropolitan communities. Using a sample of divorced women living in small, Midwestern communities, the present study tests a model of the processes whereby community structure influences parenting practices. Results obtained through structural equation modeling supported the hypotheses. High concentrations of disadvantaged people within a community were indirectly related to parenting through community social disorganization. Community social disorganization had a direct effect on quality of parenting, as well as indirect effects through negative events, access to social support, and depressed mood. The various methodological and theoretical implications of these findings are considered.     

Direct and indirect effects of unionization on the wage levels of nurses: A case study of New Jersey hospitals

This study examines the determination of wage rates for nurses in hospital employment. Of particular concern is the effect of the recent increase in unionization by nurses on their wages, both directly and indirectly via threats from competing hospitals’ unionization. To improve on earlier work, the data are disaggregated and gathered from only one state to standardize for the legal, licensing, and reimbursement systems. We also look at the difference between highly skilled professional nurses, RN’s, and more general and less professional nurses, LPN’s. The results show that working conditions and competition in the market influence the wage rate as one would expect. The unionization of nurses, however, affects the wage levels differently for the two groups. We would like to thank Professors Robert Higgs and Alan Childs of Lafayette College, Professor David Fairris of Williams College, Professor James C. Luzier of Muhlenberg College, and an anonymous referee for their helpful comments and suggestions.     

Cultural Analysis of Religious Change and Movements*

In this article I review a cultural perspective on religion and suggest that cultural analysis resolves current debates over the nature of religion as either collectivist or individualist. I use one type of cultural analysis, institutionalism, to present an interpretive overview of religious change and movements in historical contexts of global instrumental rationality, in particular the expansion of state authority. The usefulness of this approach is revealed in interpreting Protestantism in the United States, Islamic fundamentalism, and movements and trends in global Roman Catholicism. While not reflecting precisely the views of the authors of this collection, this article introduces the studies of the recent restructuring of religion in the United States (Robert Wuthnow), Islamic fundamentalisms in Iran and Syria (Mansoor Moaddel). and global Roman Catholicism (Jose Casanova).     

Force field analysis: A new way to evaluate your strategy

Force field analysis has been widely used by organization development practitioners to plan and implement organizational changes. This paper extends force field analysis to strategic management by reviewing the concept of force field analysis, discussing internal and external forces for changes in strategy, and suggesting guidelines for the use of force field analysis in organizational planning.     

A good servant but a tyrannous master: Gorse in New Zealand

The hedge plant gorse was introduced to New Zealand as a living fence and became a prominent feature of the landscape, particularly on the Canterbury Plains. Escaping from cultivation, gorse commenced its second life in New Zealand, that of a noxious weed troublesome to pastoral agriculture. In the twentieth century it came to be regarded as an invasive, exotic species that threatened indigenous plants and landscapes. Throughout its history in New Zealand, gorse, a highly significant element in the New Zealand environment, has been the object of ambivalent attitudes—a challenge to simplified conceptions of “native,” “exotic,” and “nature.”