Advances in Bayesian Time Series Modeling and the Study of Politics: Theory Testing, Forecasting, and Policy Analysis

John R. Freeman Department of Political Science, University of Minnesota, 267 19th Avenue, Minneapolis, MN 55455 e-mail: pbrandt{at}utdallas.edu (corresponding author) e-mail: freeman{at}polisci.umn.edu Bayesian approaches to the study of politics are increasinglypopular. But Bayesian approaches to modeling multiple time serieshave not been critically evaluated. This is in spite of thepotential value of these models in international relations,political economy, and other fields of our discipline. We reviewrecent developments in Bayesian multi-equation time series modelingin theory testing, forecasting, and policy analysis. Methodsfor constructing Bayesian measures of uncertainty of impulseresponses (Bayesian shape error bands) are explained. A referenceprior for these models that has proven useful in short- andmedium-term forecasting in macroeconomics is described. Oncemodified to incorporate our experience analyzing political dataand our theories, this prior can enhance our ability to forecastover the short and medium terms complex political dynamics likethose exhibited by certain international conflicts. In addition,we explain how contingent Bayesian forecasts can be constructed,contingent Bayesian forecasts that embody policy counterfactuals.The value of these new Bayesian methods is illustrated in areanalysis of the Israeli-Palestinian conflict of the 1980s.     

The different worlds of women and men: Attitudes toward pornography and responses to not a love story—A film about pornography

Men and women viewing the anti-pornography documentary Not a Love Story were surveyed about their opinions and attitudes toward pornography and toward the film. Women were found to be significantly more negative toward pornography than men, and experienced greater attitude and belief changes from the film. In addition, men's and women's attitudes toward pornography were found to differ in their factor structure; the authors infer that acceptance or rejection of pornography has different significance for men and women. Background variables such as current marriage, sex of children, and amount of pornography previously seen affected men's attitudes more than women's. The authors conclude that gender-free, ‘humanist’ standards according to which pornography could be evaluated do not exist, and that approaches to pornography control based on its role in the particular oppression of women are valid.     

Serious head and neck injury as a predictor of occupant position in fatal rollover crashes

Serious head and neck injuries are a common finding in fatalities associated with rollover crashes. In some fatal rollover crashes, particularly when ejection occurs, the determination of which occupant was driving at the time of the crash may be uncertain. In the present investigation, we describe the analysis of rollover crash data from the National Automotive Sampling System-Crashworthiness Data System for the years 1997 through 2007 in which we examined the relationship between a serious head and neck injury in an occupant and a specified degree of roof deformation at the occupant's seating position. We found 960 occupants who qualified for the analysis, with 142 deaths among the subjects. Using a ranked composite head and neck injury score (the HNISS) we found a strong relationship between HNISS and the degree of roof crush. As a result of the analysis, we arrived at a predictive model, in which each additional unit increase in HNISS equated to an increased odds of roof crush as follows: for ≥8cm of roof crush compared with <8cm by 4%, for ≥15cm of roof crush compared to <8cm by 6% and for ≥30cm of roof crush compared to <8cm by 11%. We describe two hypothetical scenarios in which the model could be applied to the real world investigation of occupant position in a rollover crash-related fatality.     

Limitations in assessment of mucosal healing in inflammatory bowel disease

An emerging parameter to define the effectiveness of new therapeutic agents in clinical trials,and by extension,for use in day-to-day clinical practice has been labeled mucosal healing.It has been hypothesized that complete healing of the intestinal mucosa in inflammatory bowel diseases should result in reduced disease complications,reduced hospitalization and reduced surgical treatment.By implication,the natural history of inflammatory bowel disease might then be altered. Measurement of mucosal healing,how...