This study experimentally examines the voluntary formation of coalitions to provide a public good when the coalition members use different voting schemes to determine their commitment. To this end, unanimity, qualified majority voting, and simple majority voting are compared with respect to the resulting public good provision level and social welfare. At first sight, in line with theoretical predictions, the experiment shows that a change in the voting scheme implemented in a coalition does not significantly change the social welfare. However, changing the majority required to determine the coalition efforts alters the depth and breadth of cooperation; coalitions under the unanimity rule are relatively large and implement moderate effort levels while coalitions with majority voting implement high effort levels but attract only a few participants.
Dannenberg, Astrid (2012), Coalition Formation and Voting In Public Goods Games, Strategic Behavior and the Environment 2, 83–105.