Is altruism evolutionarily stable ?

We develop an evolutionary approach to explain altruistic preferences. Given their preferences, individuals interact rationally with each other. By comparing the success of players with different preferences, we investigate whether evolution favors altruistic or selfish attitudes. The outcome depends on whether the individuals' interactions are strategic complements or substitutes. Altruism and self-interest are context dependent.Game Theory;Altruism;game theory

Family Versus Public Solidarity: Theory and Experiment

We present an overlapping generations model with two families who can guarantee old age support either by intra-family transfers from child to parent or via a tax-financed public pension system encompassing both families.We derive the individually and family-specific optimal decisions and present some more behavioristic hypotheses.Our experimental observations allow conclusions on (1) whether raising taxes crowds out voluntary transfers, (2) how income distributions influence family and public solidarity, and (3) whether participants prefer more to less public solidarity.voting;pensions;families;overlapping generations

Is altruism evolutionarily stable ?

We develop an evolutionary approach to explain altruistic preferences. Given their preferences, individuals interact rationally with each other. By comparing the success of players with different preferences, we investigate whether evolution favors altruistic or selfish attitudes. The outcome depends on whether the individuals' interactions are strategic complements or substitutes. Altruism and self-interest are context dependent.

Trust in the Shadow of the Courts

If contract enforcers must be randomly selected from the same population and thus are as opportunistic as ordinary traders could a system of adjudication nevertheless increase the degree to which contractual obligations on large anonymous markets are fulfilled? Adopting an indirect evolutionary approach with endogenous preference formation it can be shown that without superior behaviour of adjudicators an adjudication system can induce untrustworthy traders to behave as if trustworthy. However, in the presence of occasional mistakes adjudication will merely slow down but not fully eliminate the evolutionary advantage of untrustworthy types. Only if arbitrators become judges who receive a fixed income occasional mistakes will not favour untrustworthy types. But even then under non-optimal court politics and unfavourable parameter constellations in a low trust environment the introduction of courts may in fact contribute to the crowding out of the trustworthy.

Family Versus Public Solidarity:Theory and Experiment

We present an overlapping generations model with two families who can guarantee old age support either by intra-family transfers from child to parent or via a tax-financed public pension system encompassing both families.We derive the individually and family-specific optimal decisions and present some more behavioristic hypotheses.Our experimental observations allow conclusions on (1) whether raising taxes crowds out voluntary transfers, (2) how income distributions influence family and public solidarity, and (3) whether participants prefer more to less public solidarity.

Scope and significance of non-uniform classification practices in breast cancer with non-inflammatory skin involvement: a clinicopathologic study and an international survey

Background: The study evaluates the scope of non-uniform classification practices concerning breast carcinomas with non-inflammatory skin involvement. Patients and methods: We compared the clinical course of patients with histologically proven non-inflammatory skin involvement: 119 (65.4%) with clinically obvious ‘classical' skin changes (Group A) and 63 (34.6%) with no or only discreet changes (Group B). A questionnaire was circulated to pathology departments in 24 countries to assess the practice concerning the placement of skin- involved breast carcinomas in the TNM classification. Results: Patients in Group B showed a significantly better disease specific survival (P = 0.0002). Eighty-six respondents (70.5%) of the survey preferred the ‘histological view' and classified tumors with only histological proven skin involvement as T4b/stage IIIB. The opposing classification principle (‘clinical view'), which dictates that T4b breast cancer is a clinical diagnosis and the classical signs must be present, was supported by 31 respondents (25.4%). Conclusions: A large number of breast cancer patients with non-inflammatory skin involvement are only histologically proven and show, compared with cases exhibiting the classical clinical signs, significant differences in clinical course and prognosis. In general, both subsets were aggregated in one T category/stage (T4b/IIIB). This results in a considerable distortion of the reported statistical dat

Community projects: an experimental analysis of a fair implementation process

We define and experimentally test a public provision mechanism that meets three basic ethical requirements and allows community members to influence, via monetary bids, which of several projects is implemented. For each project, participants are assigned personal values, which can be positive or negative. We provide either public or private information about personal values. This produces two distinct public provision games, which are experimentally implemented and analyzed for various projects. In spite of the complex experimental task, participants do not rely on bidding their own personal values as an obvious simple heuristic whose general acceptance would result in fair and efficient outcomes. Rather, they rely on strategic underbidding. Although underbidding is affected by projects’ characteristics, the provision mechanism mostly leads to the implementation of the most efficient project

Resonant Inelastic X-ray Scattering from Electronic Excitations in α\alpha-RuCl3_3 Nanolayers

We present Ru $L_3$-edge resonant inelastic x-ray scattering (RIXS) measurements of spin-orbit and d-d excitations in exfoliated nanolayers of the Kitaev spin-liquid candidate RuCl$_3$. Whereas the spin-orbit excitations are independent of thickness, we observe a pronounced red-shift and broadening of the d-d excitations in layers with thickness below $\sim$7 nm. Aided by model calculations, we attribute these effects to distortions of the RuCl$_6$ octahedra near the surface. Our study paves the way towards RIXS investigations of electronic excitations in various other 2D materials and heterostructures

What happens if you single out? An experiment

We present an experiment investigating the effects of singling out an individual on trust and trustworthiness. We find that (a) trustworthiness falls if there is a singled out subject; (b) non-singled out subjects discriminate against the singled out subject when they are not responsible of the distinct status of this person; (c) under a negative frame, the singled out subject returns significantly less; (d) under a positive frame, the singled out subject behaves bimodally, either selecting very low or very high return rates. Overall, singling out induces a negligible effect on trust but is potentially disruptive for trustworthiness