Can Information Backfire? - Experimental Evidence from the Ultimatum Game

We investigate experimentally if an option to obtain free information can disadvantage a player, relative to when information is unavailable. In the Ultimatum game, the Responder chooses a minimum acceptable offer and the Proposer decides at the same time whether to obtain and use information about the minimum acceptable offer. We find that the option of using free information on average reduces Proposers’, and increases Responders’, payoff, but by less than predicted. This is due to the presence of Proposers who either refuse information or who use it in a self-servingly fair manner. Information changes the distribution of the surplus, and increases inefficiency.Information; information acquisition; value of information; Ultimatum game; fairness; self-serving fairness

Indenture as a Commitment Device in Self-Enforced Contracts: An Experimental Test

How can a principal (an agent) ensure that an agent (a principal) will work (pay up), if payment (work) precedes work (payment)? When a banknote is torn in two, each part is by itself worthless. A principal can pre-commit to payment-on-delivery, by tearing a banknote and giving the agent the first half as "prepayment"; the agent receives the completing half upon delivery of the service. This contract design is known as "indenture". It is selfenforcing and incentive-compatible. This paper experimentally tests the efficacy of the "indenture game" and its implications for cooperation in one-shot environments. We find that cooperation rates are high and stable over time. Its efficacy is moderated by expected losses due to the existence of uncooperative types.Cooperation, Experiment, Contracts, Indenture, Reciprocity

Game Harmony as a Predictor of Cooperation in 2 x 2 Games

This paper presents an experimental test of the relationship between game harmony and cooperation in 2 x 2 games. Game harmony measures describe how harmonious (non-conflictual) or disharmonious (conflictual) the interests of players are, as embodied in the payoffs: coordination games and constant-sum games are examples of games of perfect harmony and disharmony, respectively; most games are somewhere in the middle. Correlation coefficients between measured harmony and cooperation rates were above 0.8 in an experiment with games such as the Prisoner`s Dilemma, the Stag-Hunt, a coordination game and three trust games, and above 0.55 in an experiment with random games.Game harmony, Cooperation, 2 x 2 games, Trust games, Social dilemmas

Voluntary Contributions by Consent or Dissent

We study games where voluntary contributions can be adjusted until a steady state is found. In consent games contributions start at zero and can be increased by consent, and in dissent games contributions start high and can be decreased by dissent. Equilibrium analysis predicts free riding in consent games but, in contrast, as much as socially efficient outcomes in dissent games. In our experiment, inexperienced subjects contribute high in consent games and low in dissent games, but behavior converges toward equilibrium predictions over time and eventually experienced subjects contribute as predicted: low in consent games and high in dissent games. Observed deviations from equilibrium in consent games are best explained by level-k reasoning, and those in dissent games are best explained by hierarchical reasoning formalized as nested logit equilibrium.public good, contribution game, bounded rationality, mechanism

Brownian motion of a charged test particle near a reflecting boundary at finite temperature

We discuss the random motion of charged test particles driven by quantum electromagnetic fluctuations at finite temperature in both the unbounded flat space and flat spacetime with a reflecting boundary and calculate the mean squared fluctuations in the velocity and position of the test particle. We show that typically the random motion driven by the quantum fluctuations is one order of magnitude less significant than that driven by thermal noise in the unbounded flat space. However, in the flat space with a reflecting plane boundary, the random motion of quantum origin can become much more significant than that of thermal origin at very low temperature.Comment: 11 pages,no figures, Revtex

Influence in the Face of Impunity

We compare dictator and impunity games. In impunity games, responders can reject offers but to no payoff consequence to proposers. Because proposers act under impunity, we should expect the same behavior across games, but experimentally observed behavior varies. Responders indeed exercise the rejection option. This threat psychologically influences proposers. Some proposers avoid rejection by offering nothing. Others raise offers, but only when they receive feedback from responders. Responders lose this influence in the absence of feedback.This is the preprint of an article published in Economics Letters 141 (2016), pp. 119-121 available online at: http://dx.doi.org/10.1016/j.econlet.2016.02.02

Religion, discrimination and trust across three cultures

We propose that religion impacts trust and trustworthiness in ways that depend on how individuals are socially identified and connected. Religiosity and religious affiliation may serve as markers for statistical discrimination. Further, affiliation to the same religion may enhance group identity, or affiliation irrespective of creed may lend social identity, and in turn induce taste-based discrimination. Religiosity may also relate to general prejudice. We test these hypotheses across three culturally diverse countries. Participants' willingness to discriminate, beliefs of how trustworthy or trusting others are, as well as actual trust and trustworthiness are measured incentive compatibly. We find that interpersonal similarity in religiosity and affiliation promote trust through beliefs of reciprocity. Religious participants also believe that those belonging to some faith are trustworthier, but invest more trust only in those of the same religion—religiosity amplifies this effect. Across non-religious categories, whereas more religious participants are more willing to discriminate, less religious participants are as likely to display group biases

Diverse novel mesorhizobia nodulate New Zealand native Sophora species

Forty eight rhizobial isolates from New Zealand (NZ) native Sophora spp. growing in natural ecosystems were characterised. Thirty eight isolates across five groups showed greatest similarity to Mesorhizobium ciceri LMG 14989T with respect to their 16S rRNA and concatenated recA, glnll and rpoB sequences. Seven isolates had a 16S rRNA sequence identical to M. amorphae ATCC 19665T but showed greatest similarity to M. septentrionale LMG 23930T on their concatenated recA, glnll and rpoB sequences. All isolates grouped closely together for their nifH, nodA and nodC sequences, clearly separate from all other rhizobia in the GenBank database. None of the type strains closest to the Sophora isolates based on 16S rRNA sequence similarity nodulated Sophora microphylla but they all nodulated their original host. Twenty one Sophora isolates selected from the different 16S rRNA groupings produced N2-fixing nodules on three Sophora spp. but none nodulated any host of the type strains for the related species. DNA hybridisations indicated that these isolates belong to novel Mesorhizobium spp. that nodulate NZ native Sophora species

Reference Dependent Altruism

In view of behavioral patterns left unorganized by current social preference theories, we propose a theory of reference dependent altruism (RDA). With RDA, one's degree of altruism increases at reference points. It induces equity and efficiency effects that are conditional on whether or not payoffs meet reference points. We verify the theory first by experimentally analyzing majority bargaining, where observed behavior contradicts existing theories but confirms RDA. Using parameter estimates from majority bargaining, we then make out-of-sample predictions for Charness-Rabin, Engelmann-Strobel, and Bolton-Ockenfels games. RDA organizes these seemingly disparate games out-of-sample, which validates our hypothesis that pro-social behavior primarily relates to reference points

Ultimata bargaining: generosity without social motives

We show and explain how generosity beyond that explainable by social preferences can manifest in bargaining. We analyze an ultimata game with two parties vying to coalesce with a randomly chosen proposer. They simultaneously demand shares of the surplus. The proposer must then make an offer that meets at least one demand, or else the game either continues with a new round or breaks down with all earning zero. Self-interest, altruism, and inequity aversion univocally predict miniscule demands due to inter-party competition; proposers thus obtain the lion's share. We experimentally observe that proposers coalesce with the less demanding party by strategically matching demands, like ultimatum bargaining, but also give non-strategically to the other party, like dictator giving. The observations are incompatible with concave utilities, as implied by social preferences, but are compatible with reference dependent preferences