Crafting messages to fight dishonesty: A field investigation of the effects of social norms and watching eye cues on fare evasion

•The combination of descriptive social norms and watching eyes reduces fare evasion.•Descriptive social norms and watching eyes reduces also dishonesty in the die task.•Watching eye cues alone does not impact fare evasion rates.•The results strengthen the external validity of laboratory studies on dishonesty.•Fighting dishonesty could benefit from combining nudge-based interventions.