Cox, Friedman, and Sadiraj (2008) develop a model of reciprocity, „Revealed Altruism‟, which posits that a „more generous than‟ (MGT) offer elicits a „more altruistic than‟ (MAT) response. A MGT ordering is defined by two conditions. Condition a) states that MGT is ordered by the maximum potential increase in income of the recipient, or that the more you stand to receive from an offer, the more generous it is to you. Condition b) states that the increase in maximum potential income of the recipient cannot be less than the maximum potential increase in income of the proposers. In other words, Condition b) states that an offer cannot be self-serving, but it is not specified in Cox, Friedman, and Sadiraj (2008) precisely how b) affects the MGT ordering. I propose that a violation of b) is considered self-serving and is less MGT than when b) is not violated. I then experimentally study the empirical relevance of b) using two designs that hold a) constant, comparing MGT differences implied by responses. The first design is a variant of the Lost Wallet Game (Dufwenberg & Gneezy, 2000) with a negative outside option, and the second design is a modified Investment Game (Berg, Dickhaut, & McCabe, 1995) with elements of the Dictator Game implemented by Andreoni and Miller (2002). I find no empirical support that b) affects the MGT ordering.

R&D plays a dual role: First, it generates new knowledge and second, it develops a firm's absorptive capacity. Most of the existing strategic investment game models neglect, however, the second role of R&D. The aim of this paper is to incorporate the absorptive capacity hypothesis in such a model by endogenizing the spillover. A two-stage game is established and subsequently solved, looking for the subgame perfect Nash equilibria. Considering the comparative static properties of the model as well as the simulation results, a new effect appears: The "free-rider effect" of the models with exogenous spillover, which deteriorates the higher the spillover becomes, is now counteracted by the "absorptive capacity effect". It is found that firms will invest more in R&D to strengthen absorptive capacity when the spillover parameter is higher. (author's abstract) / Series: Department of Economics Working Paper Series

Les comportements sociaux coopératifs sont longtemps restés un obstacle aux modèles de choix rationnel, obstacle qu'incarnent des dilemmes sociaux où un individu suivant son intérêt personnel est incité à exploiter la coopération d'autrui à son seul avantage. Je détaillerai tout d'abord comment la coopération peut apparaître un choix sensé lorsque elle est envisagée dans un contexte naturel et réel. Un regard à travers l'anthropologie, la psychologie et la neurobiologie conduit à appréhender la coopération davantage comme une adaptation et un apprentissage que comme un défaut de rationalité. Les émotions jouent un rôle essentiel dans ces processus, et je présenterai en quoi les exprimer aide les êtres humains à se synchroniser et à coopérer. Le sourire est souvent invoqué comme exemple d'un signal universel de coopération et d'approbation, une propriété intimement liée à son expression répétée lors de tâches collaboratives. Malgré tout, on en sait encore peu sur la manière précise dont le sourire et les autres expressions interviennent dans la prise de décision sociale, et en particulier sur le traitement des situations d'incongruence où un sourire accompagnerait une défection. Ce point est le cœur de l'étude expérimentale que je rapporte dans ce manuscrit. J'ai réalisé deux expériences confrontant les participants à un dilemme social dans lequel ils pouvaient investir une somme d'argent auprès de différents joueurs informatisés susceptibles de se l'accaparer, ou, au contraire, de la rétribuer avec intérêts. Les joueurs virtuels étaient personnalisés par un visage dont l'expression pouvait changer après le choix du participant: certains affichaient ainsi des émotions incongruentes avec leur ``décision'' subséquente de rétribuer ou non l'investissement du sujet. Malgré les différences méthodologiques, ces deux expériences ont montré que les expressions incongruentes altéraient la capacité des participants à jauger la propension des joueurs virtuels à rétribuer leurs investissements après une ou plusieurs interactions. Cet effet s'est manifesté tant au travers de rapports explicites que dans les investissements effectués. Dans leurs détails, les résultats de ces expériences ouvrent de nombreuses perspectives expérimentales, et appellent à la construction d'un modèle unifié de la décision sociale face-à-face qui intégrerait les nombreuses connaissances apportées ces dernières années par l'étude des grandes fonctions cognitives, tant au niveau expérimental, théorique que neurobiologique. / For few decades, rational choice theories failed to properly account for cooperative behaviors. This was illustrated by social dilemmas, games where a self-motivated individual will be tempted to exploit others' cooperative behavior, harming them for his own personal profit. I will first detail how cooperation may rise as a reasonable --- if not rational --- behavior, provided that we consider social interactions in a more realistic context that rational choice theories initially did. From anthropology to neurobiology, cooperation is understood as an efficient adaptation to this natural environment rather than a quirky, self-defeating behavior. Because pertinent information is often lacking or overwhelming, too complex or ambiguous to deal with, it is essential to communicate, to share, and to trust others. Emotions, and their expression, are a cornerstone of humans' natural and effortless navigation in their social environment. Smiles for instance are universally known as a signal of satisfaction, approbation and cooperation. Like other emotional expressions, they are automatically and preferentially treated. They elicit trust and cooperative behaviors in observers, and are ubiquitous in successful collaborative interactions. Beside that however, few is known about how others' expressions are integrated into decision making. That was the focus of the experimental study I relate in this manuscript. More specifically, I investigated how decisions in a trust-based social dilemma are influenced by smiles which are either displayed along a cooperative or defective behavior (``congruently'' and ``incongruently'', resp.). I carried out two experiments where participants played an investment game with different computerized virtual partners playing the role of trustees. Virtual trustees, which were personalised with a facial avatar, could either take and keep participants investment, or reciprocate it with interests. Moreover, they also displayed facial reactions, that were either congruent or incongruent with their computerized ``decision'' to reciprocate or not. Even if the two experiments presented some methodological differences, they were coherent in that they both showed that participants were altered in remembering a virtual trustee's behavior if the latter expressed incongruent emotions. This was observed from participants' investments in game, and from their post-experimental explicit reports. If many improvements to my experimental approach remain to be done, I think it already completes the existing literature with original results. Many interesting perspectives are left open, which appeal for a deeper investigation of face-to-face decision making. I think it constitutes a theoretical and practical necessity, for which researchers will be required to unify the wide knowledge of the major cognitive functions which was gathered over the last decades.

La tesi presenta alcuni dei risultati di un esperimento longitudinale condotto in due carceri statunitensi tra settembre 2015 e giugno 2016. L’obiettivo dell’analisi è testare lo studio delle preferenze sociali nella cornice dell’Economia Comportamentale e della teoria dei giochi (osservazione diretta del comportamento dei soggetti chiamati a compiere delle scelte in alcune situazioni selezionate), piuttosto che attraverso risposte a questionari auto valutativi. Infatti vengono messe in relazione i comportamenti osservati nei giochi e le spiegazioni che i soggetti intervistati danno di essi. Attraverso analisi statistica si può arrivare a dire che i comportamenti osservati nei giochi non sono sempre sufficienti per evidenziare le preferenze sociali dei soggetti, così come, del resto, non lo sono le risposte narrative. La conclusione che viene tratta dall’elaborato è che osservazione diretta dei comportamenti e analisi delle narrative personali dei soggetti sono due elementi ugualmente importanti per la comprensione delle preferenze sociali e che, lungi dall’escludersi a vicenda, si completano. / The thesis presents some of the results of a longitudinal experiment conducted in two U.S. prisons between September 2015 and June 2016. The objective of the analysis is to test the efficacy of studying social preferences in the framework of behavioral Economics and game theory (direct observation of the behaviour of the subjects asked to make choices in real situations), rather than through self-evaluative questionnaires and surveys. In fact, the analysis links the behaviors observed in the games and the explanations given by the subjects. In general it can be said that the behaviors observed in the games are not always sufficient to highlight the social preferences of the subjects, as well as, moreover, are not the narrative answers. The conclusion that comes from the elaborate is that direct observation of the behaviors and analysis of the personal narratives of the subjects are two equally important tools in the study social preferences and that, far from being mutually exclusive, they complement each other.