Oath-taking for senior executives has been promoted as a mean to enhance honesty within and towards organizations. Herein we explore whether people who voluntarily sign a solemn truth-telling oath are more committed to sincere behavior when offered the chance to lie. We design an experiment to test how the oath affects truth-telling in two contexts: a neutral context replicating the typical experiment in the literature, and a "loaded" context in which we remind subjects that "a lie is a lie." We consider four payoff configurations, with differential monetary incentives to lie, implemented as within-subjects treatment variables. The results are reinforced by robustness investigations in which each subject made only one lying decision. Our results show that the oath reduces lying, especially in the loaded environment-falsehoods are reduced by fifty percent. The oath, however, have a weaker effect on lying in the neutral environment. The oath did affect decision times in all instances: the average person takes significantly more time deciding whether to lie under oath.

This paper presents the results of a laboratory experiment in which workers perform a real-effort task and supervisors report the workers' performance to the experimenter. The report is non verifiable and determines the earnings of both the supervisor and the worker. We find that not all the supervisors, but at least one third of them bias their report. Both selfish black lies (increasing the supervisor's earnings while decreasing the worker's payoff) and Pareto white lies (increasing the earnings of both) according to Erat and Gneezy ( 2009)'s terminology are frequent. In contrast, spiteful black lies (decreasing the earnings of both) and altruistic white lies (increasing the earnings of workers but decreasing those of the supervisor) are almost non-existent. The supervisors' second-order beliefs and their decision to lie are highly correlated, suggesting that guilt aversion plays a role.

This paper presents the results of a laboratory experiment in which workers perform a real-effort task and supervisors report the workers' performance to the experimenter. The report is non verifiable and determines the earnings of both the supervisor and the worker. We find that not all the supervisors, but at least one third of them bias their report. Both selfish black lies (increasing the supervisor's earnings while decreasing the worker's payoff) and Pareto white lies (increasing the earnings of both) according to Erat and Gneezy ( 2009)'s terminology are frequent. In contrast, spiteful black lies (decreasing the earnings of both) and altruistic white lies (increasing the earnings of workers but decreasing those of the supervisor) are almost non-existent. The supervisors' second-order beliefs and their decision to lie are highly correlated, suggesting that guilt aversion plays a role.