Age-period-cohort analysis: an illustration of the problems in assessing interaction in one observation per cell data

This paper discusses the specific problems of age-period-cohort (A-P-C) analysis within the general framework of interaction assessment for two-way cross-classified data with one observation per cell. The A-P-C multiple classification model containing the effects of age groups (rows), periods of observation (columns), and birth cohorts (diagonals of the two-way table) is characterized as one of a special class of models involving interaction terms assumed to have very specific forms. The so-called A-P-C identification problem, which results from the use of a particular interaction structure for detecting cohort effects, is shown to manifest itself in the form of an exact linear dependency among the columns of the design matrix. The precise relationship holding among these columns is derived, as is an explicit formula for the bias in the parameter estimates resulting from an incorrect specification of an assumed restriction on the parameters required to solve the normal equations. Current methods for modeling A-P-C data are critically reviewed, an illustrative numerical example is presented, and one potentially promising analysis strategy is discussed. However, gien the large number of possible sources for error in A-P-C analyses, it is strongly recommended that the results of such analyses be interpreted with a great deal of caution.     

Bayesian reconstruction of contingency tables with partially categorized data

This paper suggests a Bayesian approach to the reconstruction of a 2 × 2 contingency table where some of the observations are only partially categorized and others are fully categorized. In contrast, most previous Bayesian and non-Bayesian analyses of the partially categorized data problem have been concerned with estimation of the parameters that generated the data. We show in an example that estimates may not be extremely sensitive to the weight placed on prior information relative to the sample data.     

Indiana bat roosting behavior differs between urban and rural landscapes

Urban Ecosystems - Urbanization may negatively affect forest obligate bat species. We compared the roosting behavior of federally endangered Indiana bats (Myotis sodalis) in a fragmented site,...     

Whither Risk Assessment: New Challenges and Opportunities a Third of a Century After the Red Book

Six multi‐decade‐long members of SRA reflect on the 1983 Red Book in order to examine the evolving relationship between risk assessment and risk management; the diffusion of risk assessment practice to risk areas such as homeland security and transportation; the quality of chemical risk databases; challenges from other groups to elements at the core of risk assessment practice; and our collective efforts to communicate risk assessment to a diverse set of critical groups that do not understand risk, risk assessment, or many other risk‐related issues. The authors reflect on the 10 recommendations in the Red Book and present several pressing challenges for risk assessment practitioners.     

Assessment in Adult Protective Services: do multidisciplinary teams make a difference?

This study compared 2 approaches to the assessment of Adult Protective Services (APS) cases. Using administrative data from 869 cases in 2 counties in Maryland, the differences between a nurse/social worker team and a lone social worker in case disposition, risk reduction, recidivism, and cost effectiveness were examined. Lone social workers were significantly more likely to confirm financial exploitation, physical abuse, and neglect by others; while the team approach resulted in significantly greater risk reduction. No differences were observed in relation to recidivism, self-neglect and cost savings. Given limited resources, research that examines optimal staffing patterns in APS agencies is warranted.     

Understanding human ambivalence about sex: The effects of stripping sex of meaning

We offer a theoretical perspective to provide insight into why people are ambivalent about sex and why cultures regulate sex and attach symbolic meaning to it. Building on terror management theory, we propose that sex is problematic for humankind in part because it reminds us of our creaturely mortal nature. Two experiments investigated the effects of reminding people of the similarity between humans and other animals on their reactions to the physical aspects of sex. In Study 1, priming human‐animal similarities led to increased accessibility of death‐related thoughts after thinking about the physical but not romantic aspects of sex. In Study 2, when participants were reminded of similarities between humans and other animals, mortality salience resulted in decreased attraction to the physical but not romantic aspects of sex. In each study, priming thoughts about how humans are distinct from animals eliminated the association between sex and death.