See Ernest Fehr and Klaus M. Schmidt, Theories of Fairness and Reciprocity, Evidence and Economic Applications, Institute for Empirical Research in Economics, University of Zurich, Working Paper No. 75 (February 2001);

Bruno S. Frey and Stephan Meier, Pro-Social Behavior, Reciprocity, or Both? Institute for Empirical Research in Economics, University of Zurich, Working Paper No. 107 (February 2002);

Ernest Fehr and Armin Falk, Psychological Foundations of Incentives, Schumpeter Lecture, Annual Conference of the European Economic Association 2001. Examples, in addition to those cited in footnote 63 supra, are

George A. Akerlof, Labor Contracts as Partial Gift Exchange, 97 Q. J. of Econ. 543 (1982);

Rachel E. Kranton, Reciprocal Exchange: A Self-Sustaining System, 86 Am. Ec. Rev., 830 (1996);

Janet T. Landa, The Enigma of the Kula Ring in Trust, ethnicity, and identity: beyond the new institutional economics of ethnic trading networks, contract law, and gift-exchange 141-172 (1994);

Ernst Fehr, Erich Kirchler, Andreas Weichbold, & Simon Gachter, When Social Norms Overpower Competition: Gift Exchange in Experimental Labor Markets, 16 J. Labor Econ. 324 (1998). My point is narrower, that is, that the baseline response of most economists and lawyers trained to look at questions through an economic prism is disbelief, and my purpose in the analytic segment of this article is to respond to that widely held disbelief. mostly can be found at: http://www.iew.unizh.ch/wp/