2 IZA Discussion Papers
IZA Discussion Paper No. 10517
revised version published in: Experimental Economics, 2018, 21( 1), 99 -131
IZA Discussion Paper No. 1646
published as 'The economics of altruistic punishment and the maintenance of cooperation' in: Proceedings of the Royal Society B -Biological Sciences, 2008, 275 (1637), 871-878