Renegotiation Proofness and Climate Agreements: Some Experimental Evidence

The notion of renegotiation-proof equilibrium has become a cornerstone in non-cooperative models of international environmental agreements. Applying this solution concept to the infinitely repeated N-person Prisoners' Dilemma generates predictions that contradict intuition as well as conventional wisdom about public goods provision. This paper reports the results of an experiment designed to test two such predictions. The first is that the higher the cost of making a contribution, the more cooperation will materialize. The second is that the number of cooperators is independent of group size. Although the experiment was designed to replicate the assumptions of the model closely, our results lend very little support to the two predictions.

The Theory of Full International Cooperation: An Experimental Evaluation

The concept of renegotiation-proof equilibrium has become a cornerstone in recent game theoretic reasoning about the stability of international environmental agreements. Applying this solution concept to a linear version of the infinitely repeated N-person Prisoners’ Dilemma, Scott Barrett has been able to derive a number of interesting (and sometimes provocative) predictions about international cooperation to curb climate change. This paper reports the results of a laboratory experiment designed to test two central predictions from Barrett’s model. The first prediction says that the higher the cost of making a contribution, the more cooperation will materialize. The second claims that the number of cooperators is independent of group size. The experiment was designed to replicate the assumptions of Barrett’s model closely. We find that the experimental confrontation lends very little support to the two predictions

Can exit prizes induce lame ducks to shirk less? Experimental evidence

Elected representatives serving their final period face only weak incentives to provide costly effort. However, overlapping generations (OLG) models suggest that exit prizes sustained by trigger strategies can induce representatives in their final period to provide such effort. We evaluate this hypothesis using a simple OLG public good experiment, the central treatment being whether exit prizes are permitted. We find that a significantly higher number of subjects in their final period contribute when exit prizes are permitted. However, this result does not originate from use of trigger strategies. More likely explanations include gift-exchange and focal-point effects

Are Nurses More Altruistic than Real Estate Brokers?

We report results from a dictator game experiment with nurse students and real estate broker students as dictators, and Amnesty International as the recipient. Although brokers contributed substantial amounts, nurses contributed significantly more, on average 76 percent of their endowment. In a second part, subjects chose between a certain repetition of the experiment and a 50-50 chance of costly exit. About one third of the brokers and half of the nurses chose the exit option. While generosity was indeed higher among nurses, even when taking exits into account, the difference cannot readily be attributed to different degrees of altruism.dictator game, exit option, generosity, occupational differences

Maintenance of weight loss and aerobic capacity one year aft er the end of a lifestyle intervention focusing on nutritional guidance and/or exercise

The aims of this study were to: 1) investigate to what extent participants in a lifestyle intervention program, including nutritional guidance and two weekly intensive running sessions, maintain improvements in aerobic capacity and health parameters one year after the end of an intervention; and 2) identify common determinants for those participants who succeeded in weight loss maintenance. A total of 51 participants completed the 33-week intervention. One year after the end of the intervention period (1YA) 34 participants completed anthropometric measurements, 12 (8 women) in the training group (TG) and 22 (13 women) in the nutritional guidance and training group (NTG). A total of 13 participants (9 women) in the TG and 11 participants (7 women) in the NTG completed a 3000 m running test. There were no significant differences in body mass index, 3000 m running time or waist circumference between the groups 1YA. There was however, substantial variation in both groups as to what extent participants had maintained their weight loss. Higher self-efficacy and self-control in relation to food and exercise characterized those who best maintained their weight loss

Aerobic training combined with nutritional guidance as an effective strategy for improving aerobic fitness and reducing BMI in inactive adults

The aim of this study was to examine the impact of a 33-week program, which included two weekly intensive running sessions, on aerobic capacity, BMI, waist circumference and body composition in overweight and obese, inactive adults. An additional aim was to examine the additional impact of lifestyle modification education. Twenty-four participants in the Training Group (exercise only) and 27 in the Nutritional Guidance and Training Group (exercise + nutritional guidance) completed the study. Anthropometric measurements (BMI, waist circumference, visceral fat, muscle mass and fat percentage) and 3000 m running time were measured at start, after 15 weeks (BMI, waist circumference and 3000 m running time) and after 33 weeks of intervention. Significant reductions in BMI, waist circumference, fat percentage and 3000 m running time were found for both groups. A small, but insignificant, increase was found for muscle mass in both groups and visceral fat in the training group. A significant interaction effect for visceral fat was also found. Both groups improved their running time and anthropometric measurements. No significant differences were found between the groups

Effectiveness of the International Child Development Programme: Results from a randomized controlled trial

This study aimed to evaluate the effectiveness of the International Child Development Programme (ICDP), a group-based parenting programme used internationally and implemented nationally in Norway. We used a cluster randomized controlled trial in which 81 groups were randomly assigned to either the intervention or waitlist control condition after the baseline data collection. A total of 590 parents completed at least one of three questionnaires (administrated before and after ICDP and 4 months after completing the intervention). Primary outcomes included parental self-efficacy, parental emotion sensitivity and positive involvement with their child. Secondary outcomes included parents' perceptions of their relationship with the child, child-rearing conflicts and the child's psychosocial health. We found significant effects favouring the intervention arm following the intervention and at follow-up on two primary outcomes (parental self-efficacy and emotion sensitivity). For the secondary outcomes, we found a significant reduction in child-rearing conflict at the 4-month follow-up, increased closeness to the child, reduced child internalizing difficulties and increased prosocial behaviour immediately following the intervention. However, ICDP seems to have limited effects on parent-reported changes in children. We conclude that ICDP as a universal preventive programme offered to parents in groups can be effective in strengthening parental self-efficacy and improving parental emotion sensitivity.publishedVersio

Group size effects in two repeated game models of a global climate agreement

What levels of total abatement can one hope for in a global climate agreement? Some potential answers to this question are provided by game theory. This working paper contains a critical discussion of two (prominent) game models that answer the question quite pessimistically. Both models take the n-person, infinitely repeated prisoner's dilemma game as their point of departure. The first model is a full information model and utilizes the notion of a weakly renegotiation proof equilibrium. This results in the (maybe counterintuitive) prediction that an agreement that can provide high utility to the group will attract less total abatement than an agreement that can only provide low utility to the group. The second model assumes imperfect public information and utilizes the notion of a trigger level equilibrium. This results in the (more intuitive) prediction that the level of total abatements will increase with improved verification techniques, for a given player set. Still the level of total abatements decrease with an increasing player set, for a given verification technique. Empirical implications of the two models are identified, and it is argued that one should confront these with experimentally generated data in order to discriminate between the models. One reason for this is that historical data on abatement efforts in a global climate agreement do not exist since no such agreement has entered into force yet

Platform selection in the lab

Emerging literature explores experimental platform selection games. These games con- verge rapidly on the superior platform under a wide range of conditions. We replicate the remarkable results of Hossain and Morgan (2009) in which such a game tips almost perfectly to the superior platform. Next, we show that platform coordination fails when seemingly innocent increases in out-of-equilibrium payo¤s are introduced. The in ated payo¤s keep the best reply structure unchanged and do not in uence players security levels. Our de- sign allows control for the explanatory force of risk dominance. We nd that equilibrium selection theory is unable to account for coordination failure while observed behavior is con- sistent with non-rational learning. Furthermore, and contrary to the literature, we nd that e¢ ciency su¤ers when an inferior platform is granted initial monopoly