Received: 11 July 2019
Accepted: 16 October 2019
First Online: 1 November 2019
Ethics approval and consent to participate
: The study was approved by our institution’s ethics committee (Joint Ethics Committee of the Faculty of Economics and Business Administration of Goethe University Frankfurt and the Gutenberg School of Management & Economics of the Faculty of Law, Management and Economics of Johannes Gutenberg University Mainz; ExternalRef removed). Informed written consent was obtained from all participants of this study.
: Not applicable.
: The authors declare that they have no competing interests.