Bertrand Price Competition in a Social Environment

We analyze the dynamic behaviour of firms that locally interact through price competition in a social environment in an evolutionary game-theoretic model. These firms update their prices according to the behavioural rule Win Cooperate, Lose Defect (WCLD), which is often observed in experimental economics. It can be regarded as a generalized Tit-for-Tat strategy. The model can explain the simultaneous emergence of collusive behaviour, price dispersion and occasional local price wars. Price wars only last for a short period of time after which the firms start to collude again.