忠诚折扣、转售价格维持组合与非对称零售服务投资

A Combination of Loyalty Discounts and Resale Price Maintenance under Differential Retail Service Investments

忠诚折扣与转售价格维持组合可以实现零售服务异质条件下的非对称最优投资,这一新的发现不仅解决了长期困扰转售价格维持服务理论的一个难题,而且为转售价格维持反垄断效率识别提供了一个可操作的维度。当需要以转售价格维持解决零售服务"搭便车"、同时还需要以非对称零售服务投资实现异质零售服务有效供给时,如果制造商信息不完全、但零售商信息完美,两部收费与转售价格维持组合即可实现非对称最优零售服务投入;但若制造商信息不完全及零售商信息不完美同时存在,则仅有忠诚折扣与转售价格维持组合才能够保证最优零售服务投资实现。原因在于,忠诚折扣能够通过事后销量识别零售商投资是高或低,从而有效解决不完全信息条件下非对称零售服务投资的识别和差别补偿问题。相较于两部收费,忠诚折扣与转售价格维持组合不仅有利于制造商利润最大化,而且能够改善社会福利。在事前对称的市场环境中,忠诚折扣内生形成事后非对称的零售商市场结构,其中低投资零售商的降价激励强于高投资零售商,这一特征有助于识别并检验转售价格维持合约的真实动机。

How to distinguish a pro-competitive resale price maintenance(RPM)from an anticompetitive one is a difficult question faced by economists and antitrust enforcement.Although impacts of various vertical contracts together with RPM have been examined in the literature,the implications of a combination of loyalty discounts with RPM on efficiency are understudied.In this paper,we find that under imperfect information,the combination of loyalty discounts with RPM will improve efficiency over the combination of a two-part tariff(2 PT)with RPM.In particular,we consider different combinations of a 2 PT or loyalty discounts with RPM under different information environments and study their impacts on differential retail service investments.We show that,when there is information asymmetry between a manufacturer and two retailers as well as imperfect information between the two retailers,the combination of loyalty discounts and RPM can implement the industry optimal,differential retailer service investments whereas the combination of 2 PT and RPM cannot.This is because RPM imposes retail price uniformity ex post,the differential 2 PTs ex ante will induce opportunistic behavior in investment which prevents the differential retail service investments from being chosen.In contrast,the loyalty discounts can compensate differential retail service investments based on different sales ex post.Thus,the combination of loyalty discounts and RPM can implement the industry optimal outcome.This not only maximizes the manufacturer’s profits,but also improves consumer welfare over the combination of 2 PT and RPM.Our findings provide a new rationale for the loyalty discounts and RPM combination,and a solution to the dilemma of supplying differential services under RPM posed by Telser(1960).The unique impact of combining loyalty discounts with RPM has important implications for antitrust enforcement.The loyalty discounts will offer the downstream buyer a price concession only if the sales exceed certain threshold,while the collusion is to limit supply.Therefore,the loyalty discounts essentially conflict with the ultimate goal of collusion.It follows that the RPM,if combined with loyalty discounts,is not going to facilitate collusion.This feature suggests a simple test that distinguishes the RPM that promotes service from that facilitates collusion.In an ex ante symmetric setting,the combination of loyalty discounts and RPM endogenously gives rise to an ex post asymmetric retail market structure.That is,the retailer that sells more will obtain the loyalty discounts and thus invest more ex ante,while the other retailer that sells less will not get the discounts and invest less ex ante.Such asymmetric market structure and cost structure will result in different incentives to lower the price below the RPM one:the retailer enjoying the loyalty discounts will lose more for the same amount of price drop.In other words,the incentive to launch a price war from the low investment,small retailer is stronger than that of the high investment,big retailer,exhibiting an unusual"small bullies big"characteristic.As a result,we expect to observe a unilateral price undercutting from the small retailer,instead of a price war between the big and small retailers.This behavioral pattern differs from the price undercutting incentive in traditional retail market competition,which can be applied as an empirical test for the intention of RPM and help the antitrust enforcement to analyze the competition effects of RPM.All in all,our model provides a framework to analyze RPM,especially when it is combined with loyalty discounts.Some landmark RPM cases,such as Leegin,Monsanto,seem to fit our theory well.In addition,our theory offers some new insights complementing the traditional literature on RPM.