Voluntary participation and cooperation in a collective-good game.

We study the effect of voluntary participation in the context of a collective-good experiment. We investigate whether the freedom to participate in the game or not increases contribution levels and enhances their evolution. The analysis of two voluntary participation treatments supports a positive effect of an attractive exit option on both contribution levels and their sustainability. We conclude that the voluntary contribution mechanism can provide sustainable cooperation levels and that the usually observed decay of average contribution levels can be counteracted by voluntary participation in the game..Collective Goods; Cooperation; Voluntary participation ; Laboratory experiments.

Global versus local interaction in coordination games: an experimental investigation.

We study experimentally the outcome of a 50 periods repetition of a two-player coordination game, which admits two-pure strategy Nash equilibria that are Pareto-ranked: a payoff-dominant equilibrium and a risk-dominant equilibrium. The experiment consists of a 2x3 factorial design, with two different matching rules –global an local interaction–, and three sizes for the basin of attraction of the risk-dominant equilibrium. Under global interaction, each player can be matched in each period with any player in the population. Under local interaction, each player can be matched only with one of his two neighbours. Our results confirm earlier experimental results obtained under global interaction (for a survey see Ochs (1995)). On the contrary, the results contrast sharply with Keser, Ehrhart & Berninghaus (1998), who found that subjects interacting ‘locally’ with their neighbours around a circle, coordinate mostly on the risk-dominant equilibrium. Moreover, we found no evidence for a faster convergence to an equilibrium under local interaction than under global interaction. Keywords: Coordination games, Experimental economics, Evolutionary game theory, Local interactions

Road Traffic Congestion and Public Information: An Experimental Investigation

This paper reports two laboratory studies designed to study the impact of public information about past departure rates on congestion levels and travel costs. Our experimental design is based on a discrete version of Arnott, de Palma, and Lindsey’s (1990) bottleneck model where subjects have to choose their departure time in order to reach a common destination. Experimental treatments in our first study differ in terms of the level of public information on past departure rates and the relative cost of delay. In all treatments, congestion occurs and the observed travel costs are quite similar to the predicted ones. In other words, subjects’ capacity to coordinate does not seem to be affected by the availability of public information on past departure rates or by the relative cost of delay. This seemingly absence of treatment effects is confirmed by our finding that a parameter-free reinforcement learning model best characterizes individual behavior. The number of experimental subjects taking the role of drivers is four times larger in our second study than in our first study. We observe that coordination failures in our congestion situation do not become more severe when the number of drivers increases.Travel behavior; Congestion; Information in intelligent transportation systems; Laboratory experiments.

Structure d’interactions et problème de coordination : une approche expérimentale

Nous étudions expérimentalement les résultats d’un jeu de coordination à deux joueurs et deux actions par joueur répété sur 50 périodes. Ce jeu de coordination de type « chasse au cerf » possède deux équilibres de Nash en stratégie pure qui sont Pareto ordonnés : un équilibre Pareto dominant et un équilibre risque dominant. Un protocole expérimental factoriel composé de 2 x 3 traitements est utilisé afin d’étudier l’effet de la règle d’appariement (interaction globale versus interaction locale) et de la taille du bassin d’attraction de l’équilibre risque dominant (trois tailles) sur la dynamique de jeu. En interaction globale, un joueur peut interagir à chaque période avec tout autre joueur de la population alors qu’en interaction locale, il ne peut interagir qu’avec ses deux plus proches voisins. En interaction globale, nos résultats confirment ceux obtenus précédemment à savoir que i) les situations hors équilibre sont rares, ii) le choix modal en première période est la stratégie Pareto dominante, et iii) les choix de première période déterminent fortement les choix de dernière période, la distribution des choix finals se trouvant généralement dans le même bassin d’attraction que celle des choix initiaux. Les deux premiers faits stylisés s’observent également en interaction locale mais, contrairement aux dynamiques observées en interaction globale, la convention vers laquelle les choix convergent dépend fortement de la taille du bassin d’attraction de l’équilibre risque dominant. Ainsi, nous constatons une convergence vers la convention Pareto dominante lorsque les bassins d’attraction des deux équilibres sont de taille identique et une convergence vers la convention risque dominante pour le plus large des trois bassins d’attraction de l’équilibre risque dominant. Enfin, nous n’observons pas de différence significative quant à la vitesse de convergence vers un équilibre pour les deux règles d’appariement.We report the results of an experiment that examines play in a 50 periods repetition of a two-player coordination game (Stag Hunt game), which admits two pure strategy Nash equilibria that are Pareto-ranked : a payoff-dominant equilibrium and a risk-dominant equilibrium. We consider a 2x3 factorial design, with two different matching rules -global and local interaction- and three sizes for the basin of attraction of the risk-dominant equilibrium. Under global interaction, each player can be matched in each period with any player in the population. Under local interaction, each player can be matched only with his two closest neighbours. Our results confirm earlier experimental results obtained under global interaction : i) non-equilibrium outcomes are rarely observed, ii) the first period modal choice is the payoff-dominant strategy, and iii) the first period play determines strongly the steady-state which will be reached, as it generally lies in the same basin of attraction as the initial state. The two first stylised facts are also observed under local interaction but unlike the dynamics observed under global interaction, the convention towards which choices converge is strongly dependent on the size of the basin of attraction of the risk-dominant equilibrium. We observe convergence towards the payoff dominant convention when the two basins of attraction are of the same size and towards the risk dominant convention for the largest of the three basins of attraction of the risk dominant equilibrium. We found no evidence for a faster convergence under local interaction than under global interaction

Jeu du dictateur et jeu de la confiance : préférences distributives vs préférences dépendantes des croyances

International audienc

Nudge and tax in an environmental public goods experiment: Does environmental sensitivity matter? (vol 55, pg 24, 2019)

Nudge and tax in an environmental public goods experiment: Does environmental sensitivity matter? (vol 55, pg 24, 2019

Nudge and tax in an environmental public goods experiment: Does environmental sensitivity matter?

An experiment is proposed in which the subjects could contribute to a public good which could be thought of as reducing pollution, which was stochastic. A nudge (announcement of the socially optimal contribution) and a tax are implemented to improve the level of contributions. The environmental sensitivity and optimism of the subjects are also elicited. Our first result shows that the implementation of the nudge does not perform as well as the implementation of the tax. The reaction to the nudge depends directly on individuals’ environmental sensitivity, contrary to the reaction to the tax. Secondly, the nudge performs well with highly sensitive subjects only during the first half of its implementation. Lastly, the efficiency analysis shows that the implementation of the nudge significantly decreases the groups’ welfare for the least sensitive subjects, in comparison to the baseline

Voluntary participation and cooperation in a collective-good game

We study the effect of voluntary participation in the context of a collective-good experiment. We investigate whether the freedom to participate in the game or not can affect contribution levels over time. The analysis of two voluntary-participation treatments supports a noticeable effect of an attractive exit option on contribution levels. We conclude that voluntary participation can induce a recovery of cooperation levels when the payoff yielded by the exit option is high enough, so that the usually observed decay of average contribution levels can be counteracted.Social dilemma Cooperation Voluntary participation Public-good experiments

Double overreaction in beauty-contests with information acquisition: theory and experiment

International audienceCentral banks' disclosures, such as forward guidance, have a weaker effect on the economy in reality than in theoretical models. The present paper contributes to understanding how people pay attention and react to various sources of information. In a beauty-contest with information acquisition, we show that strategic complementarities give rise to a double overreaction to public disclosures by increasing agents equilibrium attention, which, in turn, increases the weight assigned to them in equilibrium action. A laboratory experiment provides evidence that the effect of strategic complementarities on the realised attention and the realised action is qualitatively consistent with theoretical predictions, though quantitatively weaker. Both the lack of attention to public disclosures and a limited level of reasoning by economic agents account for the weaker realised reaction. This suggests that it is just as important for a central bank to control reaction to public disclosures by swaying information acquisition by recipients as it is by shaping information disclosures themselves