Effectiveness of ex ante honesty oaths in reducing dishonesty depends on content

Janis H Zickfeld; Karolina A Ścigała; Christian T Elbæk; John Michael; Mathilde H Tønnesen; Gabriel Levy; Shahar Ayal; Isabel Thielmann; Laila Nockur; Eyal Peer; Valerio Capraro; Rachel Barkan; Simen Bø; Štěpán Bahník; Daniele Nosenzo; Ralph Hertwig; Nina Mazar; Alexa Weiss; Ann-Kathrin Koessler; Ronit Montal-Rosenberg; Sebastian Hafenbrädl; Yngwie Asbjørn Nielsen; Patricia Kanngiesser; Simon Schindler; Philipp Gerlach; Nils Köbis; Nicolas Jacquemet; Marek Vranka; Dan Ariely; Jareef Bin Martuza; Yuval Feldman; Michał Białek; Jan K Woike; Zoe Rahwan; Alicia Seidl; Eileen Chou; Agne Kajackaite; Simeon Schudy; Ulrich Glogowsky; Anna Z Czarna; Stefan Pfattheicher; Panagiotis Mitkidis

doi:10.1038/s41562-024-02009-0

Effectiveness of ex ante honesty oaths in reducing dishonesty depends on content

Nat Hum Behav. 2024 Oct 21. doi: 10.1038/s41562-024-02009-0. Online ahead of print.

Authors

Janis H Zickfeld¹, Karolina A Ścigała², Christian T Elbæk³, John Michael⁴, Mathilde H Tønnesen³, Gabriel Levy⁵, Shahar Ayal⁶, Isabel Thielmann⁷, Laila Nockur², Eyal Peer⁸, Valerio Capraro⁹, Rachel Barkan¹⁰, Simen Bø¹¹, Štěpán Bahník¹², Daniele Nosenzo¹³, Ralph Hertwig¹⁴, Nina Mazar¹⁵, Alexa Weiss¹⁶, Ann-Kathrin Koessler¹⁷, Ronit Montal-Rosenberg⁸, Sebastian Hafenbrädl¹⁸, Yngwie Asbjørn Nielsen², Patricia Kanngiesser¹⁹, Simon Schindler²⁰, Philipp Gerlach²¹, Nils Köbis^{14

22}, Nicolas Jacquemet^{23

24}, Marek Vranka²⁵, Dan Ariely²⁶, Jareef Bin Martuza¹¹, Yuval Feldman²⁷, Michał Białek²⁸, Jan K Woike^{14

19}, Zoe Rahwan¹⁴, Alicia Seidl^{7

29}, Eileen Chou³⁰, Agne Kajackaite³¹, Simeon Schudy^{32

33}, Ulrich Glogowsky^{33

34}, Anna Z Czarna³⁵, Stefan Pfattheicher², Panagiotis Mitkidis³

Affiliations

¹ Department of Management, Aarhus University, Aarhus, Denmark. jhzickfeld@gmail.com.
² Department of Psychology and Behavioural Sciences, Aarhus University, Aarhus, Denmark.
³ Department of Management, Aarhus University, Aarhus, Denmark.
⁴ Department of Philosophy, University of Milan, Milan, Italy.
⁵ Department of Philosophy and Religious Studies, NTNU Trondheim, Trondheim, Norway.
⁶ Baruch Ivcher School of Psychology, Reichman University, Herzliya, Israel.
⁷ Max Planck Institute for the Study of Crime, Security and Law, Freiburg, Germany.
⁸ Federmann School of Public Policy, Hebrew University of Jerusalem, Jerusalem, Israel.
⁹ Department of Psychology, University of Milan Bicocca, Milan, Italy.
¹⁰ Department of Business Administration, Ben-Gurion University of the Negev, Beersheba, Israel.
¹¹ Department of Strategy and Management, Norwegian School of Economics, Bergen, Norway.
¹² Department of Management, Prague University of Economics and Business, Prague, Czech Republic.
¹³ Department of Economics and Business Economics, Aarhus University, Aarhus, Denmark.
¹⁴ Max Planck Institute for Human Development, Berlin, Germany.
¹⁵ Questrom School of Business, Boston University, Boston, MA, USA.
¹⁶ Department of Psychology, Bielefeld University, Bielefeld, Germany.
¹⁷ Institute of Environmental Planning, Leibniz University Hannover, Hannover, Germany.
¹⁸ IESE Business School, University of Navarra, Barcelona, Spain.
¹⁹ School of Psychology, University of Plymouth, Plymouth, UK.
²⁰ Federal University of Applied Administrative Sciences, Berlin, Germany.
²¹ Fresenius University, Hamburg, Germany.
²² Center for Trustworthy Data Science and Security, University of Duisburg-Essen, Duisburg, Germany.
²³ Paris School of Economics, Paris, France.
²⁴ CES, Université Paris 1 Panthéon-Sorbonne, Paris, France.
²⁵ Faculty of Social Sciences, Charles University, Prague, Czech Republic.
²⁶ Fuqua School of Busisness, Duke University, Durham, NC, USA.
²⁷ Faculty of Law, Bar Ilan University, Ramat Gan, Israel.
²⁸ Institute of Psychology, University of Wrocław, Wrocław, Poland.
²⁹ Department of Psychology, University of Kaiserslautern-Landau, Landau, Germany.
³⁰ Batten School of Leadership and Public Policy, University of Virginia, Charlottesville, VA, USA.
³¹ Department of Economics, Management, and Quantitative Methods, University of Milan, Milan, Italy.
³² Institute of Economics, Ulm University, Ulm, Germany.
³³ CESifo Munich, Munich, Germany.
³⁴ Department of Economics, Johannes Kepler University Linz, Linz, Austria.
³⁵ Jagiellonian University, Krakow, Poland.

PMID: 39433937
DOI: 10.1038/s41562-024-02009-0

Abstract

Dishonest behaviours such as tax evasion impose significant societal costs. Ex ante honesty oaths-commitments to honesty before action-have been proposed as interventions to counteract dishonest behaviour, but the heterogeneity in findings across operationalizations calls their effectiveness into question. We tested 21 honesty oaths (including a baseline oath)-proposed, evaluated and selected by 44 expert researchers-and a no-oath condition in a megastudy involving 21,506 UK and US participants from Prolific.com who played an incentivized tax evasion game online. Of the 21 interventions, 10 significantly improved tax compliance by 4.5 to 8.5 percentage points, with the most successful nearly halving tax evasion. Limited evidence for moderators was found. Experts and laypeople failed to predict the most effective interventions, though experts' predictions were more accurate. In conclusion, honesty oaths were effective in curbing dishonesty, but their effectiveness varied depending on content. These findings can help design impactful interventions to curb dishonesty.