Altruistic Behavior Under Incomplete Information

Models to the issue of altruism which rely on externalities of well-being are rarely used explicitly. In this paper we compare such utility-based approaches with the standard approach on altruism which is based on externalities of income. Testable differences of both types of models are derived in the case of incomplete information. More specifically, applied to the Dictator Game and the Impunity Game both played under incomplete information, the utility-based based approach predicts dictators to change their behavior in comparison to Dictator Games under complete information. Under the income-based approach, behavior should not differ in the three versions of the Dictator Game. --Altruism,Incomplete Information,Consistent Expectations

Utility versus Income-Based Altruism

In Dictator Game experiments where the information status of the participants varies we find that a certain type of proposer tends to reduce his offers when the recipient has incomplete information about the pie size. We also find that a certain type of recipient tends to reject too small offers in the Impunity Game when the proposer has incomplete information about the recipient type. To explain these puzzling results we reconsider Becker's [1974] theory of altruism, which assumes that externalities are caused by other people's utility. When incomplete information about the other person is introduced, it turns out that his approach predicts – in contrast to other theories of altruism - that some altruistic persons will change their behavior as observed in our experiments. Thus, a kind of utility based altruism (and spite as its opposite form) can be assumed as the main principle governing behavior in this class of games. --

The Economics of Solidarity: A Conceptual Framework

For many people "solidarity" has become a meaningless word used in slogans - too often used without leading to any economic consequences. We show in this paper conditions under which solidarity can be a powerful instrument. In a solidary action, an individual in a group contributes to a series of actions that aims for a reallocation of scarce resources. The willingness to contribute is mainly influenced by the efficiency of the objective of the solidary action, and is enhanced by feelings of mutual exchange (solidarity) within a group. --solidarity,altruism,dynamic,mutual

Utilisation des méthodes d'extractions chimiques sélectives pour la prospection géochimique en milieu latéritique

L'étude par extractions chimiques sélectives d'échantillons latéritiques (Musongati, Burundi) permet de montrer l'association de différents éléments en traces avec certaines phases porteuses préférentielles. Elle met également en correspondance l'évolution de la cristallinité de la goethite avec le contenu en traces métalliques de ce minéral. Le respect de conditions cinétiques bien précises affine l'interprétation de données de prospection géochimique grâce à la prise en compte du type d'altération ayant affecté les horizons échantillonné