Trafﬁc and Parking Fine Collection: Are Social Norms More Effective than Enforcement? Presenter: Yinjunjie (Jacquelyn) Zhang Co-author: Mathias G. Sinning Abstract
This paper presents the results of a randomized controlled ﬁeld trial designed to test the effects of social norms and enforcement messages on the collection of trafﬁc and parking ﬁnes in the Australian Capital Territory (ACT). The trial targets a population of individuals who committed a trafﬁc or parking offence and who ignored ﬁne collection notices from the ACT government for more than six months. Consistent with the literature, receiving a social norms letter or an enforcement letter increases ﬁne payments relative to a control group that does not receive a letter. Our analysis of heterogeneous treatment effects indicates that addressing social norms does not change the behavior of young offenders and those who committed a speeding offence, among other groups. While social norms messages are not effective for speciﬁc groups, our ﬁndings suggest that enforcement messages are generally an effective tool to increase ﬁne payments.