Credible assignments can improve efficiency in laboratory public goods games

This paper reports an experiment investigating how assignments improve economic efficiency in a modified version of the standard voluntary-contributions mechanism. The experiment uses a non-binding message that makes common information assignments in the repeated game. A credible assignment is one actually followed by the participants. It turns out to be difficult to credibly assign the symmetric efficient outcome in four person cohorts, but we did discover one assignment that was credible in the last match of the evolutionary repeated game.