Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This research investigates the effects of the group size and the magnitude of the volunteering cost in a controlled large-scale laboratory experiment, where subjects play the volunteer’s dilemma only once. The experiment varies group sizes ranging from groups of 3 to about 100, and 2 different cost/benefit ratios. Results show that high cost reduces volunteering probability only in the smallest groups, but not for other group sizes. Furthermore, I find non-monotonic group size effect on the individual volunteering decisions. These findings are compared to the predictions produced by symmetric mixed-strategy Nash equilibrium, procedural rationality and quantal response equilibrium.