Template-Type: ReDIF-Paper 1.0 Author-Name: Jens Gudmundsson Author-Name-First: Jens Author-Name-Last: Gudmundsson Author-Email: jg@ifro.ku.dk Author-Workplace-Name: Department of Food and Resource Economics, University of Copenhagen Author-Name: Jens Leth Hougaard Author-Name-First: Jens Leth Author-Name-Last: Hougaard Author-Email: jlh21@nyu.edu Author-Email: jlh@ifro.ku.dk Author-Workplace-Name: NYU-Shanghai, China Author-Workplace-Name: Department of Food and Resource Economics, University of Copenhagen Title: Enabling reciprocity through blockchain design Abstract: We introduce a reciprocity protocol, an innovative approach to coordinating and sharing rewards in blockchains. Inherently decentralized and easy to implement, it puts emphasis on incentives rather than forcing specic sharing rules from the outset. Analyzing the non-cooperative game the protocol induces, we identify a robust, strict, and Pareto-dominant symmetric equilibrium. In it, even self-centered participants show extensive reciprocity to one another. Thus, despite a setting that is generally unfavorable to reciprocal behavior, the protocol manages to build trust between the users by taking on a role akin to a social contract. Length: 28 pages Creation-Date: 2020-12 Revision-Date: 2021-02-09 File-URL: http://okonomi.foi.dk/workingpapers/WPpdf/WP2020/IFRO_WP_2020_14.pdf File-Format: Application/pdf Number: 2020/14 Classification-JEL: C62, C72, D02, D63, D91 Keywords: Blockchain, reciprocity, protocol design, Nash equilibrium Handle: RePEc:foi:wpaper:2020_14