Original article Is generosity involuntary? Tomas Broberg a , Tore Ellingsen b , Magnus Johannesson b, ⁎ a Actagon AB, Stockholm, Sweden b Department of Economics, Stockholm School of Economics, Sweden Received 11 January 2006; received in revised form 20 June 2006; accepted 24 July 2006 Available online 13 November 2006 Abstract We estimate the distribution of exit reservation prices in a dictator game. The mean exit reservation price equals 82% of the dictator game endowment and only 36% of subjects have exit reservation prices consistent with selfish or social preferences. © 2006 Elsevier B.V. All rights reserved. Keywords: Dictator game; Exit option; Generosity JEL classification: C91; D64 1. Introduction In the dictator game, one subject decides how to allocate an endowment between herself and another person (the recipient). The game is one-shot, anonymous and the recipient cannot retaliate. Conventional selfish preferences predict that the dictator will keep the entire pie. This prediction has been refuted in numerous experiments. On average, subjects typically give between 10% and 30% of the endowment to the other player (see Camerer, 2003 for an overview of results). To explain this finding, researchers have argued that subjects are altruistic or have a taste for fairness. Several formal models of social preferences Economics Letters 94 (2007) 32 – 37 www.elsevier.com/locate/econbase ⁎ Corresponding author. Department of Economics, Stockholm School of Economics, Box 6501, SE-113 83 Stockholm, Sweden. Tel.: +46 8 7369443; fax: +46 8 302115. E-mail address: magnus.johannesson@hhs.se (M. Johannesson). 0165-1765/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.econlet.2006.07.006