Social Influence in Trustors’ Neighborhoods

Economists have often analysed the impact that the spread of beliefs and behaviors have on the equilibrium and performance of markets. Recent experimental studies on peer pressure in groups of agents interacting in investment and gift exchange games (Mittone and Ploner, 2011, Gachter et al. 2010) have proved that the imitation of partners’ behaviors can have substantial effects on reciprocity, thus confirming that the effects of information also need to be studied in games where social preferences play a fundamental role. The aim of this paper is to ascertain whether trust is affected by contagion and herding in small groups of trustors who can observe each other’s choices over time. We account for three important factors of trustors’ preferences, namely: risk attitude, generosity and expected trustworthiness. Using our data we test the basic hypothesis that an individual's propensity to trust recipients in the Trust Game can be affected by the observed behavior of other trustors. Our results confirm that trust is affected by contagion effects. Furthermore, we find that specific types of agents (generous or untrusting) more often imitate the same type, when positioned in the same group. Finally, we find that untrusting individuals are less affected by their peers compared to generous individuals, and they imitate less even when positioned in groups of agents who have the same characteristics.