A framework for the analysis of self-confirming policies

Theory and Decision - This paper provides a general framework for analyzing self-confirming policies. We study self-confirming equilibria in recurrent decision problems with incomplete information...     

Reality check. Evaluating a school-based gang prevention model

The Gang Resistance Education and Training (G.R.E.A.T.) program is a school-based gang prevention initiative developed in 1991 through the collaborative efforts of the Bureau of Alcohol, Tobacco, and Firearms, the Federal Law Enforcement Training Center, and the Phoenix Police Department. Uniformed law enforcement officers, certified as G.R.E.A.T. instructors, teach the 9-week curriculum to middle students. In 1994, the National Institute of Justice funded a national evaluation of the G.R.E.A.T. program. The process evaluation component of this larger study is reported. First, results of on-site observations of the G.R.E.A.T. Officer Training program, including an overview of the training activities, and the authors' assessment of the training process are reported. Second, observations of the implementation of the program by officers at six sites are reported. Of primary concern was whether the program delivered to students was similar to the program taught to the officers during the G.R.E.A.T. Officer Training.     

Disability, Eugenics and the Current Ideology of Segregation: a modern moral tale

Recently, an amalgamation of articles have appeared in a wide range of publications linking together community and school inclusion, and facilitated communication research as an unholy trinity of anti-empiricism eroding the disability fields. The authors of these critiques suggest that there exists a scientific basis for state institutions, segregated learning and a non-critical acceptance of traditional interpretations of expressive ability on the part of people with disabilities. In this article we expose not science, but an ideology of segregated control behind these claims. This ideology permeates the disabilityrelated professions and is cloaked in the language of the natural sciences. We trace this use of the natural sciences to the eugenics movement of the early twentieth century and explore the legacy of the ideology of control as it impacts current understanding of disability.     

Bayesian estimation of the linear regression model with an uncertain interval constraint on coefficients

This article considers Bayesian inference in the interval constrained normal linear regression model. Whereas much of the previous literature has concentrated on the case where the prior constraint is correctly specified, our framework explicitly allows for the possibility of an invalid constraint. We adopt a non-informative prior and uncertainty concerning the interval restriction is represented by two prior odds ratios. The sampling theoretic risk of the resulting Bayesian interval pre-test estimator is derived, illustrated and explored. The authors are grateful to the editor and the referee for their helpful comments.     

Bayesian MARS

A Bayesian approach to multivariate adaptive regression spline (MARS) fitting (Friedman, 1991) is proposed. This takes the form of a probability distribution over the space of possible MARS models which is explored using reversible jump Markov chain Monte Carlo methods (Green, 1995). The generated sample of MARS models produced is shown to have good predictive power when averaged and allows easy interpretation of the relative importance of predictors to the overall fit.     

The EPA Health Risk Assessment of Methylcyclopentadienyl Manganese Tricarbonyl (MMT)

This paper describes the U.S. Environmental Protection Agency's assessment of potential health risks associated with the possible widespread use of a manganese (Mn)-based fuel additive, methylcyclopentadienyl manganese tricarbonyl (MMT). This assessment was significant in several respects and may be instructive in identifying certain methodological issues of general relevance to risk assessment. A major feature of the inhalation health risk assessment was the derivation of Mn inhalation reference concentration (RfC) estimates using various statistical approaches, including benchmark dose and Bayesian analyses. The exposure assessment component used data from the Particle Total Exposure Assessment Methodology (PTEAM) study and other sources to estimate personal exposure levels of particulate Mn attributable to the permitted use of MMT in leaded gasoline in Riverside, CA, at the time of the PTEAM study; on this basis it was then possible to predict a distribution of possible future exposure levels associated with the use of MMT in all unleaded gasoline. Qualitative as well as quantitative aspects of the risk characterization are summarized, along with inherent uncertainties due to data limitations.     

Systematic planning and re-organization

In the last decade wages and salaries have more than doubled in most industrial countries. The amount of capital behind each person in industry has in many countries increased even more, partly to rationalize and compensate for the higher manpower costs. This high rate of investment made discount rates increase 50 – 100 per cent in most industrialized countries in the same period. On the other hand low-cost countries have steadily been pushing more and better products into the international markets. This increases competition. The strongest competition and challenge, however, may come from new technology, new materials, new products and above all from better management.

This development leads to a profit-squeeze for the static company. It gives smaller margins for slow and wrong decisions, and demands a dynamic forward-looking management that understands how to organize, how to develop and involve individual human resources, and how to draw up and use objectives, goals, plans, and programmes, both for present and future growth and progress.

In this article, which is based on management and consultant experience, the focus is put on the need of developing and using as management tools systematic planning and reorganization.     

Pathways to a Stable Union? Pregnancy and Childbearing Among Cohabiting and Married Couples

This study analyzes the stability of cohabiting and marital unions following a first birth. But unlike previous research, it compares the subsequent trajectories of unions that began with a pregnancy to those in which conceptions came after coresidence. The U.S. data from the 2006–2010 and 2011–2013 cross-sectional files of the National Survey of Family Growth indicate that roughly 1-in-5 first births were associated with rapid transitions from conception into either cohabitation or marriage. Moving in together following a pregnancy—especially an unintended one—is unlikely to lead to marital success or union stability. Compared with marital unions, dissolution rates following birth were particularly high for couples who entered a cohabiting union following conception. Only a small minority of these couples married (i.e., less than one-third), and these marriages experienced high dissolution rates. The results also suggest that the most committed cohabiting couples got married after finding themselves pregnant, leaving behind the most dissolution-prone cohabiting couples. The American family system is being transformed by newly emerging patterns of fertility among cohabiting couples.     

Changes in Product Attributes and Costs as Drivers of New Product Diffusion and Substitution

Diffusion theory has typically focused on how communication, internal or external to a social system, leads to adoptions and diffusion of an innovation. We develop a diffusion and substitution model based on a somewhat different perspective. In some cases, progressive improvements in product attributes and/or continual cost reduction seem to be a key driver of the diffusion process. For example, after introduction of the 5.25‐inch disk drive, its capacity continually increased, and accordingly, so did customer willingness‐to‐pay. Our model is based on a linear reservation price framework, in which a product is described by its depth (defined as the difference between a product̂s maximum reservation price and its production cost), and its breadth (related to the slope of its reservation price curve), indicating how broadly it appeals across various customer segments. Because of changes in product depths and breadths over time, customers who previously preferred the old product may later prefer the new product, thus creating the diffusion process. While the Bass model describes diffusion as a function of the coefficients of innovation and imitation, in our model, it is described by the coefficients of depth and breadth (the rates of change in relative depth and breadth), along with an S‐coefficient that we associate with the technology S‐curve. We fit our model to data from the disk‐drive and the microprocessor industries.