Testing a policy intervention in the lab: differences between students and non-students in switching bank accounts

The reliance on student samples has long been a subject of debate in experimental approaches to studying behaviour. We contribute to this discussion by looking at differences in financial behaviour between a student and a non-student sample in three sets of lab experiments conducted in Spain, Germany and Poland (n=857). Participants from both samples switched more often and made better financial decisions after they received a message encouraging them to switch financial service providers. While the size of the effect on switching frequency was comparable between the two samples, the effect on switching quality was significantly stronger on non-students. Further analysis suggests this is due to a better performance of students before the prompt leaving less room for improvement by the reminder. Results suggest that experimental evidence derived from students should be generalized with caution.