Trends in American family size diversity

Population Research and Policy Review - How diverse is American society and are Americans becoming more or less diverse? Contemporary discussions claim high and increasing diversity, but analyze...     

Homeless violence and the informal rules of street life

Successful adaptation to street life requires that risk of violence, an often present aspect of this lifestyle, be reduced to as low a level as possible. This means knowing the informal rules which permit avoiding the pitfalls of street life. It is argued in this paper that safety and security are a function of interactions occurring within a specific place, with particular associates, and involving safe and unsafe behavior. Carelessness with respect to any of these factors can result in victimization. These issues are discussed using survey and ethnographic data collected in Chattanooga.     

Reducing Conservatism in Risk Estimation for Mixtures of Carcinogens

The excess cancer risk that might result from exposure to a mixture of chemical carcinogens usually must be estimated using data from experiments conducted with individual chemicals. In estimating such risk, it is commonly assumed that the total risk due to the mixture is the sum of the risks of the individual components, provided that the risks associated with individual chemicals at levels present in the mixture are low. This assumption, while itself not necessarily conservative, has led to the conservative practice of summing individual upper-bound risk estimates in order to obtain an upper bound on the total excess cancer risk for a mixture. Less conservative procedures are described here and are illustrated for the case of a mixture of four carcinogens.     

Mortality Risks Induced by Economic Expenditures

Existing evidence shows that lower incomes are associated with higher mortality risks. This paper examines the implications for fatalities when the relationship is interpreted as an induced relationship, meaning that lower incomes will on average lead to higher mortality risks. A model is developed for estimating the number of fatalities possibly induced by economic expenditures. This model accounts for different allocations of the expenditures on family units with varying income levels. Illustrative calculations provide insights about the possible significance of fatalities induced by economic expenditures. These results suggest that some expensive regulations and programs intended to save lives may actually lead to increased fatalities. Important caveats to reduce the likelihood of misinterpreting or misusing the results are included.     

Fitting the Two-Stage Clonal Expansion Model Based on Exact Hazard to the ED01 Data Using SAS NLIN

The two-stage clonal expansion model is a popular model for carcinogenesis data. One common form of this model is based on the approximate hazard function. In certain situations, this formulation is not appropriate, and the exact hazard should be applied. However, the difficulty of implementing the model based on the exact hazard has deterred many from using it. This paper presents a program implementing the exact hazard model for piecewise constant dosing using SAS, a package that is readily available to most that are interested in this type of analysis. Also, an analysis of the ED₀₁ data is presented using this program, and comparisons are made to an earlier analysis based on the approximate hazard. By allowing for an independent background tumor mechanism, an excellent fit to the bladder tumor incidence data was obtained.     

A Multiattribute Utility Analysis of Alternative Sites for the Disposal of Nuclear Waste

Five potential sites nominated for the Nation's first geologic repository for disposing of nuclear waste are evaluated using multiattribute utility analysis. The analysis was designed to aid the Department of Energy in its selection of 3 sites for characterization, a detailed data-gathering process that will involve the construction of exploratory shafts for underground testing and that may cost as much as $1 billion per site. The analysis produced insights into the relative advantages and disadvantages of the nominated sites and clarified current uncertainties regarding repository performance.