Focusing Climate Negotiations on a Uniform Common Commitment Can Promote Cooperation

International cooperation on the reduction of greenhouse gas emissions, disarmament, or free trade needs to be negotiated. The success of such negotiations depends on how they are designed. In the context of international climate change policy, it has been proposed [e.g., M. L. Weitzman J. Assoc. Environ. Resour. Econ. 1, 29-49 (2014)] that shifting the negotiation focus to a uniform common commitment (such as a uniform minimum carbon price) would lead to more ambitious cooperation. Yet, a proof-of-concept for this important claim is lacking. Based on game theoretical analyses, we present experimental evidence that strongly supports this conjecture. In our study, human subjects negotiate contributions to a public good. Subjects differ in their benefits and costs of cooperation. Participation in the negotiations and all commitments are voluntary. We consider treatments in which agreements are enforceable, and treatments in which they have to be self-enforcing. In both situations, negotiating a uniform common commitment is more successful in promoting cooperation than negotiating individual commitments (as in the Paris Agreement) and complex common commitments that tailor the commitment to the specific situation of each party (as attempted with the Kyoto Protocol). Furthermore, as suggested by our model, a uniform common commitment benefits most from being enforced

An updated analysis of NN elastic scattering data to 1.6 GeV

An energy-dependent and set of single-energy partial-wave analyses of $NN$ elastic scattering data have been completed. The fit to 1.6~GeV has been supplemented with a low-energy analysis to 400 MeV. Using the low-energy fit, we study the sensitivity of our analysis to the choice of $\pi NN$ coupling constant. We also comment on the possibility of fitting $np$ data alone. These results are compared with those found in the recent Nijmegen analyses. (Figures may be obtained from the authors upon request.)Comment: 17 pages of text, VPI-CAPS-7/

eBay users form stable groups of common interest

Market segmentation of an online auction site is studied by analyzing the users' bidding behavior. The distribution of user activity is investigated and a network of bidders connected by common interest in individual articles is constructed. The network's cluster structure corresponds to the main user groups according to common interest, exhibiting hierarchy and overlap. Key feature of the analysis is its independence of any similarity measure between the articles offered on eBay, as such a measure would only introduce bias in the analysis. Results are compared to null models based on random networks and clusters are validated and interpreted using the taxonomic classifications of eBay categories. We find clear-cut and coherent interest profiles for the bidders in each cluster. The interest profiles of bidder groups are compared to the classification of articles actually bought by these users during the time span 6-9 months after the initial grouping. The interest profiles discovered remain stable, indicating typical interest profiles in society. Our results show how network theory can be applied successfully to problems of market segmentation and sociological milieu studies with sparse, high dimensional data.Comment: Major revision of the manuscript. Methodological improvements and inclusion of analysis of temporal development of user interests. 19 pages, 12 figures, 5 table

Efficiency in a forced contribution threshold public good game

We contrast and compare three ways of predicting efficiency in a forced contribution threshold public good game. The three alternatives are based on ordinal potential, quantal response and impulse balance theory. We report an experiment designed to test the respective predictions and find that impulse balance gives the best predictions. A simple expression detailing when enforced contributions result in high or low efficiency is provided

Individual determinants of social fairness assessments : the case of Germany

In this contribution we study the determinants of how individuals assess the social fairness of a given income distribution. We propose an analytical framework distinguishing between potential impact factors related to the following fields: first fairness preferences, second beliefs on the sources of economic success and the functioning of democracy and third selfinterest. We test this framework on representative survey data for Germany for the years 1991, 2000 and 2004. Our results indicate that self-interest, beliefs and fairness preferences jointly shape fairness assessments. In addition, a number of personal characteristics are found to be important: Compared to their western fellow citizens, people born in GDR have a more critical view at social fairness. A particularly strong impact is related to the belief on the functioning of the democratic system. This points an important role of procedural fairness for the acceptance of a given distribution

Don't tax me? : Determinants of individual attitudes toward progressive taxation

This contribution empirically analyses the individual determinants of tax rate preferences. For that purpose we make use of the representative German General Social Survey (ALLBUS) that offers data on the individual attitudes toward progressive, proportional, and regressive taxation. Our theoretical considerations suggest that beyond self-interest, information, fairness considerations, economic beliefs and several other individual factors drive individual preferences for tax rate structures. Our empirical results indicate that the self-interest view does not offer the sole explanation for the heterogeneity in attitudes toward progressive taxation. Rather, we show that the choice of the favoured tax rate is also driven by fairness considerations