EDB: A Case Study in Communicating Risk

This is a report on the Environmental Protection Agency's (EPA's) efforts to communicate with the public about the risks of ethylene dibromide (EDB), what the agency said it was doing about these risks and what information the public actually received through television and newspapers. Although special in many ways, the EDB case illustrates the problems that regulatory agencies have when they must take regulatory action and assure the public that the risks in question are being dealt with adequately. It also illustrates issues that the press faces. Above all, it illustrates the barriers to communication presented by the different perspectives of regulatory agencies and individuals and the types of information they each are most interested in.     

Family Therapy Process in a Family Therapy Seminar

The interaction between leaders and members in a year-long family therapy seminar is systematically compared to the process that unfolds between therapist and family during the course of family therapy. A five stage developmental process common to both is postulated and described: (1) Battle for Structure, (2) Naive Enthusiasm, (3) Conflictual Frustration, (4) Task Orientation, and (5) Mutuality. The dynamic elements of each stage are analyzed and factors affecting their development are identified. It is concluded that this five stage process occurs in all similar groups, but that the content of each stage may vary widely from group to group.     

Discrimination of AR,MA and ARMA time series models

The problem of discrimination between two stationary ARMA time series models is considered, and in particular AR(p), MA(p), ARMA(1,1) models. The discriminant based on the likelihood ration leads to a quadratic form that is generally too complicated to evaluated explicitly. The discriminant can be expressed approximately as a linear combination of independent chi–squared random varianles each with one degree of freedom, the coefficients, of which are eigenvalues of cumbersome matrices. An analytical solution which gives the coefficients approximately is suggested.     

Analysis of stock market indices through multidimensional scaling

Two similarity measures are employed to compare historic stock market indices over time. The more traditional Euclidean similarity is employed to provide a reference. As a comparison, dynamic time warping is introduced as a similarity measure. Multidimensional scaling is employed to compare these dissimilarities on 15 financial indices sampled daily over a 10-year period. In addition to investigating the whole period, 1-year tranches are also considered. This analysis is compared to a recent study of Machado et al. [Analysis of stock market indices through multidimensional scaling, Commun. Nonlinear Sci. Numer. Simul. 16(12) (2011), pp. 4610–4618], who examined these same indices using correlation as a similarity measure. It is suggested that this approach may be problematic. Doubt is also cast on the efficacy of the ‘histogram’ similarity they also propose.