There are often "gains from sharing" underutilized goods with others. People routinely share tools, media, gear, electronics, toys, space, and vehicles with relatives, friends, and neighbors, and the internet is opening up new opportunities to share them with strangers. Drawing on the work of...

A number of outstanding puzzles in economics may be resolved by recognizing that where members of a group benefit from mutual adherence to a social norm, agents may obey the norm and punish its violators, even when this behavior cannot be motivated by self-regarding, outcome-oriented...

Some philosophers and social scientists have stressed the importance for good government of an altruistic citizenry that values the well being of one another. Others have emphasized the need for incentives that induce even the self interested to contribute to the public good. Implicitly most...