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 study argues that parents have a desire for dividing equally between their children, and that this motive applies to transfers of gifts inter vivos. We suggest that the equal division motive competes with traditional altruism: support to the child or the children with greatest needs. When...

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...

Empirical evidence is provided for the importance of non-reciprocal pro-social behavior of individuals in an anonymous, n-person pure public good setting. A unique panel data set of 136,000 observations is matched with an extensive survey. Even under anonymous conditions, a large number of...

Fundraising interventions may lift donations and/or shift their composition and timing, making it important to study their effect across charity space and time. We find that major fundraising appeals lift total donations, but surprisingly shift donations to other charities across time. To...

Decisions to donate time or money for charitable purposes are typically seen as make-or-buy decisions, implying that there should be a clear distinction between individuals engaging in one of these two forms of giving and that this distinction should be somehow linked to opportunity costs. But...

We present the first causal evidence on the persistent impact of enduring competition on prosociality. Inspired by the literature on tournaments within firms, which shows that competitive compensation schemes reduce cooperation in the short-run, we explore if enduring exposure to a competitive...

This paper provides first firm-level evidence of the links between income inequality and the patterns of trade and export prices. We identify a theoretical mechanism behind these links, which suggests that a more unequal income distribution leads to higher average prices. We test the theory...

We study charitable giving within social groups. Exploiting a unique dataset, we establish three key relationships between social group size and fundraising outcomes: (i) a positive relationship between group size and the total number of donations; (ii) a negative relationship between group size...

The provision of social incentives in the workplace, where performance benefits a charitable cause, has been frequently used in modern organizations. In this paper, we quantify the impact of social incentives on performance under two incentive schemes: piece rate and a winner-take-all...