Group size and gossip strategies: An ABM tool for investigating reputation-based cooperation

n an environment in which free-riders are better off than cooperators, social control is required to foster and maintain cooperation. There are two main paths through which social control can be applied: punishment and reputation. Using a Public Goods Game, we show that gossip, used for assortment under three different strategies, can be effective in large groups, whereas its efficacy is reduced in small groups, with no main effect of the gossiping strategy. We also test four different combinations of gossip and costly punishment, showing that a combination of punishment and reputation-based partner selection leads to higher cooperation rates.