each other's payoff. A positive, negative or zero weight represents altruism, spite or complete selfishness, respectively …) payoff can only increase or remain unchanged with an increasing degree of altruism. …

-play communication: numerical (tabular) only, and verbal and numerical. We find that either kind of pre-play communication increases … trusting, trustworthiness, or both, in inter-subject comparisons, but that the inclusions of verbal communication generates …

-play messages. In a laboratory experiment, we modify communication by making the sending of messages optional and costly. Even small …We study communication in a two-player coordination game with Pareto-ranked equilibria. Prior research demonstrates … that efficient coordination is difficult without communication but obtains regularly with (mandatory) costless pre …

We introduce opportunities for pre-play communication and to enter binding or non-binding contracts in trust games, and … find (a) communication increases trusting and trustworthiness, (b) contracts are unnecessary for trusting and trustworthy …

laboratory experiment in which subjects lack any private material incentive to report partners' actions, we find that most …

preferences requires an improved understanding. We conduct an experiment in which individuals in small laboratory "societies …