1 Announcement, Observation, and Honesty in the Voluntary Contributions Game By Laurent Denant-Boemont, David Masclet and Charles Noussair * August 2008 Abstract In this paper, we study the effect of pre-play announcements and ex-post observation of decisions on voluntary public good provision. We find that requiring announcements, in conjunction with making contribution decisions public, has a significantly positive effect on the average level of contributions. Those treatments, in which announcements were elicited, permit the truthfulness of subjects’ announcements to be measured. We find that high contributors are more honest, the truthfulness of others is reciprocated with greater honesty, and announcements are more honest when contribution decisions are observable. 1. Introduction Social dilemmas are situations in which a divergence exists between the outcomes that result when individual choices are based on self-interest and when they are based on group-interest. * Denant-Boemont: Université Rennes 1, Rennes, France. E-mail : Laurent.Denant-Boemont@univ-rennes1.fr Masclet: Université Rennes 1, Rennes, France. E-mail: david.masclet@univ-rennes1.fr Noussair: Department of Economics, Faculty of Economics and Business Administration, Tilburg University, P.O.Box 90153, 5000 LE Tilburg, The Netherlands. E-mail C.N.Noussair@uvt.nl. We thank a anonymous referee, Gary Bornstein