This paper considers a dynamic model of the evolution of open source software projects, focusing on the evolution of quality, contributing programmers, and users who contribute customer support to other users. Programmers who have used open source software are motivated by reciprocal altruism to...

Altruists and envious people who meet in contests are symbionts. They do better than a population of narrowly rational individuals. If there are only altruists and envious individuals, a particular mixture of altruists and envious individuals is evolutionarily stable.

In public good games, voluntary contributions tend to start off high and decline as the game is repeated. If high contributors are matched, however, contributions tend to stay high. We propose a formalization predicting that high contributors will self-select into groups committed to charitable...

This paper presents a formal theory of reciprocity. Reciprocity means that people reward kind actions and punish unkind ones. The theory takes into account that people evaluate the kindness of an action not only by its consequences but also by the intention underlying this action. The theory...

We show that once interfamily exchanges are considered, Becker's rotten kids mechanism has some remarkable implications that have gone hitherto unnoticed. Specifically, we establish that Cornes and Silva's (1999) result of efficiency in the contribution game amongst siblings extends to a setting...

This paper combines several large-scale surveys with different identification strategies to shed new light on the determinants of cooperative behavior. We provide evidence indicating that the well-being maximizing level of trust is above the income maximizing level. Higher trust is also linked...

Allowing for a free choice of the recipient's gender in a dictator game (N = 508), we find that women show a substantial gender biased towards females. Adding a charity recipient to the possible choices, the charity becomes the primary recipient and overall transfers increase. Yet, conditioning...

We report experimental findings on the role of charitable promises in bargaining settings. We vary the enforceability of such promises within variants of ultimatum games where the proposer suggest a split between himself, the responder and a char-itable donation. By reneging on initial pledges,...

Pay-what-you-want schemes can be a useful tool to finance high quality and independent news media without restricting readership, therefore guaranteeing maximum diffusion. We conduct a field experiment with the Italian information site lavoce.info to explore how to structure a campaign in a way...