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.

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...

The competition for donations between charities is tough. Yet, little is known about how giving behavior is affected by competition between charities. Do people have a need to satisfy their demand for giving by contributing to a particular charity? Or can the demand for doing good be satisfied...

We explore whether natural human competitiveness can be exploited to stimulate charitable giving in a controlled laboratory experiment involving three different treatments of a sequential dictator game. Without disclosing the actual amounts given and kept, in each period players are publicly...

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 investigate the quality provision behavior and its implications for the occurrence of collusion in competitive health care markets where providers are assumed to be altruistic towards patients. For this, we employ a laboratory experiment with a health care market framing where subjects decide...

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

We study a two-period bargaining game where buyers and sellers employ real estate agents to help them determine the sales price of a house. We find that agents are less likely to provide aggressive bargaining advice to their client when they receive percentage commissions and when they work for...

Most economic models are based on the self-interest hypothesis that assumes that all people are exclusively motivated by their material self-interest. In recent years experimental economists have gathered overwhelming evidence that systematically refutes the self-interest hypothesis and suggests...