The paper presents a simulation of the dynamics of impersonal trust. It shows how a “trust and reciprocate” norm can emerge and stabilize in populations of conditional cooperators. The norm, or behavioral regularity, is not to be identified with a single strategy. It is instead supported by several conditional strategies that vary in the frequency and intensity of sanctions.

The paper presents a simulation of the dynamics of impersonal trust. It shows how a "trust and reciprocate" norm can emerge and stabilize in populations of conditional cooperators. The norm, or behavioral regularity, is not to be identified with a single strategy. It is instead supported by several conditional strategies that vary in the frequency and intensity of sanctions.

v. 1. Opuscula logica, physica, allegorica, alia -- v. 2. Opuscula psychologica, theologica, daemonologica.

We report on an experiment examining whether individuals can solve a simple signal extraction problem of the type found in models with imperfect information. In one treatment, subjects must form point predictions based on observing both public and private signals, while in another they receive the same information but must decide on the weight to attach to each signal, which then determines their point prediction. We find that, at the aggregate level, signal extraction provides a good characterization of subjects’ behavior (...) in both treatments, but at the individual level, there is considerable heterogeneity in subjects’ ability to perform signal extraction. (shrink)

This paper investigates behavior in finitely repeated simultaneous and sequential-move prisoner’s dilemma games when there is one-sided incomplete information and signaling about players’ concerns for fairness, specifically, their preferences regarding “inequity aversion.” In this environment, we show that only a pooling equilibrium can be sustained, in which a player type who is unconcerned about fairness initially cooperates in order to disguise himself as a player type who is concerned about fairness. This disguising strategy induces the uninformed player to cooperate in (...) all periods of the repeated game, including the final period, at which point the player type who is unconcerned about fairness takes the opportunity to defect, i.e., he “backstabs” the uninformed player. Despite such last-minute defection, our results show that the introduction of incomplete information can actually result in a Pareto improvement under certain conditions. We connect the predictions of this “backstabbing” equilibrium with the frequently observed decline in cooperative behavior in the final period of finitely repeated experimental games. (shrink)