Collusion under monitoring of sales
研究企业价格私有、销量公开的不完全监控下合谋能否维持，发现对称惩罚无法维持合谋，而非对称惩罚（销量超额企业补偿不足企业）可以，这解释了赖氨酸和维生素等卡特尔的实际运作。
Collusion under imperfect monitoring is explored when firms' prices are private information and their quantities are public information; such an information structure is consistent with several recent price‐fixing cartels, such as those in lysine and vitamins. For a class of symmetric oligopoly games, it is shown that symmetric equilibrium punishments cannot sustain any collusion. An asymmetric punishment is characterized that does sustain collusion and it has firms whose sales exceed their quotas compensating those firms with sales below their quotas. In practice, cartels could have performed such transfers through sales among the cartel members.