Characterization of social choice sets in terms of individuals' maximal sets: The fixed agenda framework

In this paper we analyze the explicit representation of fixed agenda social choice correspondences under different rationality assumptions (independence, Pareto optimality, etc.). It is well known that, under some of these assumptions, the existence of dictators, oligarchies or individuals with veto power can be proven ([6] and [10]); but only a partial characterization of the social choice set is obtained. We establish a relationship between the social choice set and the individuals' maximal sets, which explicitly describes a fixed agenda social choice correspondence that satisfies these rationality assumptions. Received: 30 December 1997/Accepted: 20 December 1999     

The therapeutic value of women's adult friendships

Abstract

In 1980, thirty‐five years after the end of World War II, the long‐term impact of war‐trauma on individuals’ lives led to concern about Post‐Traumatic Stress Disorder. While the focus here is not on “disorders,” it is on interactive patterns of “defensive” caretaking behaviors which contribute to intergenerational transmission of anxiety, silence and losses related to the Holocaust. In this long‐term group, defensive caretaking patterns are conceptualized as second‐generation behaviors which focus on parental needs thereby avoiding addressing second‐generation vulnerabilities. Relevant concepts of Sullivan, Winnicott, Bion and Fairbairn are applied. In an innovative trauma group design, defensive caretaking patterns are illustrated through clinical examples and interventions by the therapist as a “validating object” work to mitigate transmission to still the next generation.     

Toward an understanding of the etiology and treatment of psychological dysfunction among single teenage mothers: Part 1, a review of the literature

Abstract

This paper, the first of a two‐part series to be published in sequential issues of the journal, reviews the recent intervention literature about single teenage mothers who are psychologically dysfunctional. It emphasizes the interplay of social, economic and developmental factors as stressors in the lives of these young women and explores some of the issues that need to be addressed in constructing effective therapeutic programs. The second paper describes an intervention program consisting of long‐term developmentally‐oriented groups for single teenage mothers and their children.     

PRICE MATCHING AND THE DOMINO EFFECT IN A RETAIL GASOLINE MARKET

Using gasoline station price data collected eight times per day for 103 d for 27 stations in Guelph, Ontario, it is found that, consistent with an informal theory of competitive gasoline pricing, stations set prices to match a small number of other stations. However, these matched stations are not necessarily the closest. While retailers frequently respond to price changes within 2 h, many take considerably longer. Finally, while price decreases do ripple across the market like falling dominos, increases propagate across the city based more on geographic location and source of price control than on proximity to leaders of these increases. ( JEL L13, L40, L81)     

A semiparametric approach to hidden Markov models under longitudinal observations

We propose a hidden Markov model for longitudinal count data where sources of unobserved heterogeneity arise, making data overdispersed. The observed process, conditionally on the hidden states, is assumed to follow an inhomogeneous Poisson kernel, where the unobserved heterogeneity is modeled in a generalized linear model (GLM) framework by adding individual-specific random effects in the link function. Due to the complexity of the likelihood within the GLM framework, model parameters may be estimated by numerical maximization of the log-likelihood function or by simulation methods; we propose a more flexible approach based on the Expectation Maximization (EM) algorithm. Parameter estimation is carried out using a non-parametric maximum likelihood (NPML) approach in a finite mixture context. Simulation results and two empirical examples are provided.     

Complying with voluntary codes of conduct: Corporate strategies for the Valdez Principles

The Valdez Principles is the latest of a series of voluntary codes of conduct that have been enunciated by various advocacy groups to guide the behavior of business enterprises. These principles provide guidelines on corporate conduct towards the environment and present a corporation with critical choices. This study suggests alternative strategies that firms may adopt to cope with this new code. Experience with the Sullivan and MacBride Principles is analyzed to serve as the basis to predict corporate response to the Valdez Principles.     

Social ties, task-related communication and first job performance of young engineers

This study investigated the relationships among social ties, task-related communication, and first industrial job performance of a group of young engineers by utilizing a cooperative (coop) engineering program as a natural study. The coop arrangement allowed the researcher to examine the work behavior of these young engineers with similar academic training who were working on comparable work assignments in the same set of organizations.The study found that the job performance of the coop engineers was related to the pattern of work- related communication but not the total number of contacts. Specifically, high performance new engineers were integrated more broadly into the interpersonal communication networks than low performance new engineers. Moreover, high performance new engineers exhibited communication patterns similar to those of high performance veteran engineers working on similar types of technical work. Social ties with the company staff was found to be related positively with job performance, but social ties with other coop engineers was found to be related negatively with job performance, a result which challenges an implicit assumption often made by researchers and managers about the organizational socialization of newcomers. Overall, this study provides an integrative framework for relating social ties and communication as key factors for understanding the job performance of young engineers and presents a methodology for assessing their organizational assimilation.     

Final report of the Color Additive Scientific Review Panel

The Color Additives Scientific Review Panel considered whether there was information sufficient to perform a carcinogenic risk assessment on the colors D&C Red No. 19 (R-19), D&C Red No. 37 (R-37), D&C Orange No. 17 (O-17), D&C Red No. 9 (R-9), D&C Red No. 8 (R-8) and FD&C Red No. 3 (R-3) and to evaluate the assessments sent to FDA as part of the petitions for use of the colors for drug and external uses by the Cosmetic, Toiletry and Fragrance Association (CTFA). There is a lack of human data concerning the colors for making a human health assessment, so the assessments are based upon the extrapolation of animal data. The risk assessments are determined for exposure to single chemicals. Excluded from consideration are possible effects from exposure to multiple chemicals, such as co-carcinogenesis, promotion, synergism, antagonism, etc. In the light of recent efforts in establishing a consensus in risk assessment, the Panel has determined that the CTFA assessments for R-10, O-17, and R-9 are consistent with present acceptable usages, although it questions some of the assumptions used in the assessments. The Panel identified a number of general assumptions made, and discusses their validity, their impact on total uncertainty, and the potential options to address the gaps in understanding that necessitate the assumption. The Panel also derived revised risk estimates using more "reasonable" assumptions than "worst-case" situations, for 90th percentile and average exposure. For those assumptions that are easily quantifiable, the Panel's estimates are less than an order of magnitude lower than the CTFA risk estimates, indicating that the underestimates and overestimates of the CTFA risk estimates tend to balance each other. The impact of most of the assumptions is not quantifiable. The assessment for R-3 is complicated by the fact that there is no good skin penetrance study for this color. It was assumed that the penetrance is similar to that of another water-soluble xanthene color, R-19. It is expected that the absorption of the color is not likely to exceed that of the smaller molecule, R-19. Therefore, the risk estimates are similar to the CTFA estimates, but with different reasoning. The estimates for R-8 and R-37 are different from the others in that there is a lack of any exposure or toxicological information on these colors.(ABSTRACT TRUNCATED AT 400 WORDS)     

Scenarios in Europe—Who uses them and why?

The authors of this article describe a study of European companies the aim of which was to review the extent of multiple scenario analysis in company planning. They describe the differences in planning between users and non-users of the system, and analyse the benefits and drawbacks of using the system.