The implications of irreversibility in emergency response decisions

The irreversibility effect implies that a decision maker who neglects the prospect of receiving more complete information at later stages of a sequential decision problem will in certain cases too easily take an irreversible decision, as he ignores the existence of a positive option value in favour of reversible decisions. This option value represents the decision maker's flexibility to adapt subsequent decisions to the obtained information. In this paper we show that the economic models dealing with irreversibility as used in environmental and capital investment decision making can be extended to emergency response decisions that produce important irreversible effects. In particular, we concentrate on the decision whether or not to evacuate an industrial area threatened by a possible nuclear accident. We show in a simple two-period evacuation decision model that non-optimal conclusions may be drawn when evacuation is regarded as a `now or never decision'. The robustness of these results is verified by means of a sensitivity analysis of the various model parameters. The importance of `options thinking' in this decision context is illustrated in an example.     

Stability and Variability of Adolescents' Affiliation with Delinquent Friends: Predictors and Consequences

The effects of stability versus change in adolescents' affiliation with delinquent or nondelinquent friends over a two-year period (T1–T2) on delinquent behavior one year later (T3) were examined. In addition, T1 predictors of stability and change in the affiliation with delinquent or nondelinquent friends from T1 to T2 were assessed. Participants were 152 adolescents (77 girls, mean age 12.1 years at T1). Friends' delinquent behavior was assessed through friends' self-reports. The T1 predictor variables included adolescents' own delinquent behavior, attitude toward delinquent behavior, and parental monitoring. Adolescents' friendship affiliations at T2, but not at T1, predicted delinquent behavior at T3, suggesting a recency effect of friendship affiliation. Attitude toward delinquent behavior at T1 was the main predictor of stability versus change in adolescents' affiliation with delinquent or nondelinquent friends from T1 to T2.     

An Infinite Decision Puzzle

We tell a story where an agent who chooses in such a way as to make the greatest possible profit on each of an infinite series of transactions ends up worse off than an agent who chooses in such a way as to make the least possible profit on each transaction. That is, contrary to what one might suppose, it is not necessarily rational always to choose the option that yields the greatest possible profit on each transaction.     

Distributional orderings: an approach with seven flavors

We examine individuals?? distributional orderings in a number of contexts. This is done by using a questionnaire-experiment that is presented to respondents in any one of seven ??flavors?? or interpretations of the basic distributional problem. The flavors include inequality, risk, social welfare and justice.     

Ellsberg games

In the standard formulation of game theory, agents use mixed strategies in the form of objective and probabilistically precise devices to conceal their actions. We introduce the larger set of probabilistically imprecise devices and study the consequences for the basic results on normal form games. While Nash equilibria remain equilibria in the extended game, there arise new Ellsberg equilibria with distinct outcomes, as we illustrate by negotiation games with three players. We characterize Ellsberg equilibria in two-person conflict and coordination games. These equilibria turn out to be related to experimental deviations from Nash equilibrium play.     

The Structural Determinants of Mortality in Japanese Prefectures

This cross-sectional multivariate analysis of age- and sex-standardized mortality for the 47 Japanese prefectures explores and tests the hypotheses that structural pluralism and differentiation, interpreted as dimensions of social problem solving capacity, determine lower mortality rates, controlling on the availability of medical facilities. The postulated explanatory principle is that participation in community problem-solving optimizes the biological functioning of the residents, which fosters better health. A factor analysis generated two factors (plus a third index of medical facilities) that measure the structural dimensions. Regression analysis showed that pluralism predicted lower mortality for both males and females, but differentiation gave contradictory results. Surprisingly, medical facilities predicted higher male mortality. A control on the more recently industrialized and the hyper-urbanized prefectures refined the analysis so that the differentiation factor predicted consistently and the spurious correlation between medical facilities and male mortality dissolved.     

Illness and the Interactionist Vocation

The disenchantment of our times is described as a contest between what are called the ride and the story. The ride represents an array of desires to treat the body as a project for perpetual enhancement and medicine as a venue of commodity capitalism. The story imagines illness as a moral project. The interactionist vocation is thus placed in the context of what Weber called our fate: how do we confront the moral dilemma of our present moment?     

Arbitrage and global cones: Another counterexample

Chichilnisky (1997) claims that another variant of her condition limiting arbitrage is necessary and sufficient for existence of equilibrium and nonemptiness of the core in an economy with short sales allowing half lines in indifference surfaces. Her proof, however, is based on a proposition purporting to relate her notion of “global cone” (see Chichilnisky (1997) for references) to the Page-Wooders “increasing cone.” In this paper, we present a counterexample showing that parts (i) and (ii) of Chichilnisky's proposition are false. Thus, Chichilnisky's claimed result is without proof. Received: 18 August 1997/Accepted: 30 January 1998