Data and Code for: Ten isn’t large! Group size and coordination in a large-scale experiment

We provide experimental evidence on coordination within large groups that could proxy the atomistic nature of real-world markets. We use a bank-run game where the two pure-strategy equilibria can be ranked by payoff and riskdominance and a sequence of public announcements introduces stochastic sunspot equilibria. We find systematic group-size effects that theory fails to predict. When the payoff-dominant strategy is risky enough, the behavior of small groups is uninformative of the behavior in large groups: unlike ‘smaller’ groups of size 10, larger groups exclusively coordinate on the Pareto inferior strategy and never coordinate on sunspots.