Flipping and ex post aggregation

We show that Bayesian ex post aggregation is unstable with respect to refinements. Suppose a group of Bayesians use ex post aggregation. Since it is a joint problem, each agent's problem is captured by the same model, but probabilities and utilities may vary. If they analyze the same situation in more detail, their refined analysis should preserve their preferences among acts. However, ex post aggregation could bring about a preference reversal on the group level. Ex post aggregation thus depends on how much information is used and may keep oscillating (“flipping”) as one keeps adding more information. Received: 16 April 2002/Accepted: 27 May 2002     

On strategy-proofness and essentially single-valued cores: A converse result

In a general model of indivisible good allocation, S?nmez (1999) established that, whenever the core is nonempty for each preference profile, if an allocation rule is strategy-proof, individually rational and Pareto optimal, then the rule is a selection from the core correspondence, and the core correspondence must be essentially single-valued. This paper studies the converse claim of this result. I demonstrate that whenever the preference domain satisfies a certain condition of `richness', if the core correspondence is essentially single-valued, then any selection from the core correspondence is strategy-proof (even weakly coalition strategy-proof, in fact). In particular, on the domain of preferences in which each individual has strict preferences over his own assignments and there is no consumption externality, such an allocation rule is coalition strategy-proof. And on this domain, coalition strategy-proofness is equivalent to Maskin monotonicity, an important property in implementation theory. Received: 22 February 2000/Accepted: 22 January 2002 I am grateful to Ryo-ichi Nagahisa, Shinji Ohseto, Hiroshi Ono, Tomoichi Shinotsuka and Shigehiro Serizawa for valuable comments. And I am indebted to two anonymous referees for useful suggestions. Especially, I owe the present proof of Lemma 2 to one referee. I also thank Yukihiko Funaki, Atsushi Kajii, Mamoru Kaneko, Eiichi Miyagawa, Tatsuyoshi Saijo, Manimay Sengupta, Yves Sprumont, Yoshikatsu Tatamitani, Manabu Toda, Takashi Ui, Takehiko Yamato, Naoki Yoshihara and the participants of the seminars in Hokkaido University, Kansai University, ISER (Osaka University), Otaru University of Commerce and Tsukuba University. All errors are my own responsiblity.     

Decision analysis for practical negotiation application

The family of decision analysis techniques can be applied effectively to support practical negotiators in international settings. These techniques are most appropriate in support of the prenegotiation phase, when parties are diagnosing the situation, assessing their own plans and strategies, and evaluating likely reactions and outcomes. The paper identifies how these approaches have and can be used to assist negotiation practitioners, offers a rationale for the application of decision analytic approaches in terms of the particular analytical requirements of the prenegotiation period, suggests how these process-oriented tools can be integrated with substantive tools, and discusses ways in which these tools can be presented and delivered to practitioners in a practical and confidence-building manner.     

Student perceptions of the danger of drug use: a factor analysis.

Australian secondary school students from three Year levels were asked to rate the danger involved in various uses of alcohol, tobacco, inhalants, marijuana and other illicit drugs. These ratings were then factor analyzed for each Year level. The results showed a more refined discrimination among the older students, with type of drug and frequency of use being important considerations. Familiarity was a major consideration for the younger students. The cognitive factors derived from the data are consistent with expectations based on the gateway theory of drug use.     

The dilemma of recognition: Administrative categories and cultural diversity

Governments around the world combat inequality by means of group-specific redistribution. Some pursue redistribution that benefits groups, but also wish to avoid accentuating or even recognizing group distinctions. This poses a dilemma that they try to resolve by adjusting the category system used to target redistribution. There are three types of adjustment: accommodation (the multicultural approach), denial (the ideal-typical liberal solution), and replacement (a compromise). In replacement the targets of redistributive policies are constructed to avoid accentuation or recognition of inconvenient group distinctions, but still allow redistribution that benefits these groups. Replacement is increasingly in demand around the world because the disadvantages of multiculturalism are becoming apparent while denial is hard to sustain in the face of group inequality. The actual effect of replacement is little researched and less understood, however. Does it resolve the dilemma of recognition? Two examples–India and Nigeria–where replacement has been tried ever since the 1950s cast doubt on its viability.     

Stress at work and psychological and immunological parameters in a group of Norwegian female bank employees

This study concerned the immunological correlates of stress and work. Self reported stress, emotional state, ego-strength, and defensiveness were examined in relation to measures of cellular immunity (T-cell response to Con A and number of T4 and T8 cells) and humoral immunity (concentrations of immunoglobulins and complement components in plasma) in a group of 96 Norwegian female bank employees. The analyses showed that workload, the stress factor with the highest group mean, was associated with number of T-cells, while strain due to body posture during work was related to concentrations of IgM and C3. Further, depression was significantly correlated with IgM concentration and T-cell number, and anxiety with C3 concentration. T-cell activity was the immunological parameter most consistently associated with psychological well-being, showing positive correlations with defensiveness and ego-strength and negative correlations with anxiety and depression. In conclusion, T-cell number and concentrations of IgM and C3 were sensitive to both work-related stress experience and emotional distress. Coping abilities, indicated by the MMPI Ego-strength scale and emotional distress, were reflected in T-cell activity; insufficient coping was associated with low T-cell activity.