Provision of step-level public goods with continuous contribution

Twelve groups of five subjects each participated in a nonco-operative game in which each member of a group receives the same endowment and must then decide independently and anonymously how much of it to contribute to the group benefit. Regardless of the size of his or her contribution, each member receives the same reward if, and only if, the sum of contributions is equal to or larger than a prespecified provision threshold. The results show that the level of contribution depends on the provision threshold, and that it increases when contributions are not restricted to be all-or-none. We present, discuss, and competitively test two models for this class of social dilemmas, one postulating maximization of expected utility and the other yielding an equitable solution.     

Ethical considerations in neuroimaging and its impact on decision-making for neonates

Neuroimaging can now provide information about structure and function. Despite new and improved neuroimaging technologies applicable to the newborn, predictions about later cognition, learning, social and emotional behavior, and neuromuscular capabilities, based on images of a fetus inside or a newborn outside the womb, are fraught with difficulties that go beyond technical ones. The interpretation of neuroimages may be necessary but it is not sufficient for decision-making related to the withholding or withdrawing of medical support for neonates. As the explanatory reach of neuroimaging increases, there will still need to be consideration of ethical issues as they relate to the best interests of the neonate and the neonate's parents, the quality of life of the neonate and non-beneficial treatment. Once this is appreciated, the boundary between the technical and the ethical will be less often disputed.     

Self-enhancement among high-exposure survivors of the September 11th terrorist attack: resilience or social maladjustment?

The authors examined self-enhancing bias as a predictor of adjustment among individuals in or near the World Trade Center during the September 11, 2001, terrorist attacks. Resilience was defined from categorical and continuous analyses of both participant self-report and friend and relative ratings of adjustment. Self-enhancement was associated with a resilient outcome, ratings of better adjustment prior to September 11th, greater positive affect, and reduced perceptions of social constraints. Additional analyses indicated that self-enhancers' reduced symptom levels were fully mediated by their low perceived social constraints. However, consistent with previous evidence suggesting a social cost to self-enhancement, at 18 months post-September 11th, self-enhancers' friends and relatives also rated them as decreasing in social adjustment and as being less honest.     

The role of illness perceptions in the attachment-related process of affect regulation

Abstract

Based on the predictions of the attachment theory and the Common Sense Model of illness perceptions, the current study focused on the role played by illness perceptions in explaining the path linking attachment orientations to negative affect during recovery from cardiac illness. We predicted two putative mechanisms: (1) illness perceptions would mediate the direct association between attachment-related insecurity (especially attachment anxiety) and levels of distress at follow-up and (2) illness perceptions would interact with attachment orientations (attachment avoidance in particular) in explaining patients' distress. The sample consisted of 111 male patients admitted to the Cardiac Care Unit of the Meir Medical Center, located in the central region of Israel. Patients completed a measure of attachment orientations during hospitalization (baseline). One month later, patients' illness perceptions were measured. Patients' depression and anxiety symptoms were measured at baseline and at the six-month follow-up. The associations between attachment-related anxiety and anxiety symptoms at follow-up were fully mediated by illness perceptions. Attachment-related avoidance was found to interact with illness perceptions in the prediction of depressive symptoms at follow-up. The findings shed light on the possible dynamics among personality, cognitive appraisals, and affect regulation efforts when coping with illness.     

Effects of cooperation and competition on responsibility attribution after success and failure

Pairs of Ss cooperated (Experiment I) or competed (Experiment II) in a response-matching task whose outcome either exceeded (Success condition), met (Neutral condition), or did not reach (Failure condition) a prior-established expected outcome level. Afterwards, Ss attributed responsibility for their outcomes. It was found under both cooperation and competition that neutral outcomes tended to produce situational attribution, and success produced self-attribution. However, failure produced partner attribution under cooperation but situational attribution under competition. The results were discussed from the standpoint of two general theories of responsibility attribution, the first emphasizing problem solving based on cues, and the second emphasizing motivational biases.     

Deterministic vs probabilistic strategies in detection

A binary detection task, free from sensory components, is investigated. A deterministic model prescribing a fixed cutoff point is confirmed; a probabilistic model, which generalizes Lee’s micromatching model for externally distributed stimuli, is rejected.     

Models for deferred decision making

Deferred decision theory assumes two simple hypotheses, observations that are purchased sequentially, losses for incorrect terminal decisions, and a constant loss per observation which may depend on the true hypothesis. After every observation, the decision maker may either make a terminal decision and incur a terminal loss if he is incorrect or purchase another observation; his objective is to minimize subjectively expected loss.     

Decision policies minimizing risk in a multistage betting game

Considered in this paper is a decision task which has been employed to study multistage betting behavior. When the task commences, a decision maker (DM) is provided with some capital x (x > 0) which he is required to allocate over m (m > 1) mutually exclusive and collectively exhaustive alternatives, each of which occurs with probability p_i (p_i > 0, i = 1,…, m; Σ_i=1^mp_i = 1). If the amount y_i is allocated to alternative i (y_i ≥ 0, Σ_i=1^my_i = x) and alternative i obtains, DM's capital for the next stage of the game becomes y_ir_i, where r_i (r_i > 0) is the return per unit allocated to alternative i. The task consists of N stages.Defining risk in terms of the mean and variance of DM's bets, and assuming that the minimization of risk is DM's objective, decision policies satisfying this objective are derived in closed form and their testable properties are briefly discussed.     

Public good provision in inter‐team conflicts: Effects of asymmetry and profit‐sharing rule

A fundamental problem in organizations is designing mechanisms for eliciting voluntary contributions from individual members of a team who are entrapped in a social dilemma. To solve the problem, we utilize a game‐theoretical framework that embeds the traditional within‐team social dilemma in a between‐team competition for an exogenously determined prize. In equilibrium, such competition enhances the incentive to contribute, thereby reducing free‐riding. Extending existing literature, we focus on asymmetric competitions between teams of unequal size, and competitions between more than two teams. Comparing two protocols for sharing the prize—egalitarian and proportional profit‐sharing rules—we find that (i) free‐riding diminishes and (ii) team members contribute more toward their team's effort when they belong to the larger team and when the profit‐sharing rule is proportional. (iii) Additionally, under the egalitarian profit‐sharing rule team members contribute more than predicted by the equilibrium solution. We discuss implications of our findings for eliciting contributions in competitive environments. Copyright © 2009 John Wiley & Sons, Ltd.