Women's paid work and the timing of births

It has been suggested that work-motivated women may shorten their birth intervals to allow a faster return to the workforce. This paper: (i) considers the circumstances under which such contraction would be expected; (ii) argues that British conditions in the 1940s to 1970s were favourable to the adoption of this strategy, among others; (iii) discusses some methodological issues arising in the empirical treatment of the question; and (iv) presents the results of analyses of work and maternity history information, which suggest that during the post-war period, labour-force participation was associated with both a contraction and a lengthening of birth intervals.     

The Decline of Deference: The Political Context of Risk Communication

Risk communication is seen as an important adjunct to the process of siting locally noxious facilities. To understand how risk communication might function in such a process, one needs to understand the political context that gives rise to public opposition to such facilities in the first place. This analysis draws on a variety of data to describe the decline of deference, a situation in which a hostile and alienated public is mobilized primarily through ad hoc voluntary organizations, and is increasingly reluctant to defer important decisions to institutional elites. Risk communication programs must be designed to offset the trends that result in the decline of deference. This conclusion differs markedly from the conventional wisdom that risk communication is merely a device for providing information to citizens so sthat they may make more rational decisions.     

Families and family study in international perspective

Many changes are occurring in the world's families. Some observers feel that the changes are destructive, whereas others see them as leading to new opportunities and understanding. Issues in international family studies include regional limitations and the various aspects of doing research cross‐culturally. Knowledge regarding certain categories of families, inheritance, and the social psychology of families is incomplete. There are, however, some universals and universal or worldwide changes, including movement toward individual partner choice, more divorces, lower fertility, and greater opportunities for women.     

The Politics of Illegal Dumping: An Environmental Justice Framework

Studies of the intersection between environmental hazards and community demographics have concluded that environmental inequality is prevalent in communities across the United States. While these studies offer persuasive indicators of environmental inequality, we still have little understanding of the social forces involved in the production of these unequal outcomes. Drawing on a case study of a community of color facing illegal dumping, I propose an environmental justice framework to explain the social dynamics that produced this outcome.     

Nuclear Plant PRA: How Far Has It Come?

Nearly ten years have passed since the publication in August 1974 of the draft Reactor Safety Study (WASH 1400), the first detailed attempt to apply probabilistic risk assessment (PRA) techniques to estimate the public risks posed by commercial nuclear power plants. Now is an opportune time to look back and see how PRA has fared over these ten years. We will not attempt to pass judgement on how the Reactor Safety Study report itself has withstood the test of time, as that task is best left to others less directly involved in preparing the report. Instead, we will examine advances in the understanding, acceptance, and utilization of PRA techniques, as well as technical advances in PRA methods. Some of the significant insights gained from PRAs will be discussed. Finally, some observations on the future of PRA will be offered.     

Prevention of Childhood Mental Disorders: A Literature Review Reflecting Hope and a Vision for the Future

Mental illness takes its emotional and financial toll on the 7.5 million children presently inflicted with a mental disorder in the United States, their families, and society as a whole. Resources and a vision for preventive research has been limited, but the tide appears to be turning. The following paper reviews the literature on prevention and resiliency related to children's mental disorders and outlines some of the recent recommendations from The Institute of Medicine (1994) in regards to the urgency of their proposed agenda for preventive intervention research in the area of child and adolescent mental disorders. Recommendations and implications for policy makers, researchers, and practitioners are considered.     

LOG-LINEAR MODELS FOR MEAN AND DISPERSION IN MIXED POISSON REGRESSION MODELS

This paper is concerned with the analysis of repeated measures count data overdispersed relative to a Poisson distribution, with the overdispersion possibly heterogeneous. To accommodate the overdispersion, the Poisson random variable is compounded with a gamma random variable, and both the mean of the Poisson and the variance of the gamma are modelled using log linear models. Maximum likelihood estimates (MLE) are then obtained. The paper also gives extended quasi-likelihood estimates for a more general class of compounding distributions which are shown to be approximations to the MLEs obtained for the gamma case. The theory is illustrated by modelling the determination of asbestos fibre intensity on membrane filters mounted on microscope slides.     

The statistician and the computer

This paper reviews the impact of the computer on the analysis and interpretation of data. It suggests the need for professonal statisticians to recognize that almost all future analysis of data will be carried out by non-statisticians with the aid of statistical program packages. Therefore, the emphasis of statistical training for scientists, engineers, administrators and decision-makers should be on the design of data collection and the choice of appropriate methods of analysis. Both in the teaching of statistics and in the development of computer programs for statistical analysis there are important and urgent tasks to be addressed by professional statisticians.     

Comparison of the Cancer Risk of Methylene Chloride Predicted from Animal Bioassay Data with the Epidemiologic Evidence

Methylene chloride has been shown to be a lung and liver carcinogen in the mouse; yet, the current epidemiologic data show no adverse health effects associated with chronic exposure to this compound. Hearne et al. have compared the results of a large mortality study on occupational exposure to methylene chloride to the human risk predictions based on the rodent bioassay to point out the inconsistency between the animal toxicologic and human epidemiologic data. The maximum number of lung and liver cancers predicted due to methylene chloride exposure based on the rodent bioassay data was 24 compared to 14 deaths from these cancers actually observed in the Hearne et al. epidemiology study. We assess the minimum risk detectable by the human study in order to calculate the upperbound potency of methylene chloride and compare it to the potency derived from the bioassay data. Results from the epidemiology study imply an upperbound potency of 1.5 x 10(-2) per ppm, compared to 1.4 x 10(-2) per ppm calculated using the most conservative analysis of the animal data. We conclude that the negative epidemiology study of Hearne et al. is not sufficiently powerful to show that the risk is inconsistent with the human risk estimated by modeling the rodent bioassay data. Specifically, the doses to which the workers were exposed, the population studied, and the latency period were not adequate to determine that the risks are outside the bounds of the risk estimates predicted by low-dose modeling of the animal data.