The scope for collusion under different pricing schemes

We analyze and compare the incentives to collude under different pricing schemes in a differentiated-products market where customers have elastic demand. We show that allowing firms to set two-part tariffs as opposed to linear prices facilitates collusion at maximum prices independent of the degree of differentiation. However, compared to a situation where firms can only set fixed fees that are independent of the quantity purchased, collusion at maximum prices is less sustainable with two-part tariffs. The results have important implications for competition policy where the perspective—static or dynamic—may be crucial.