Price Discrimination with Differentiated Products: Definition and Identification
指出差异化产品价格歧视的两种常用标准（绝对价格差和百分比加成）结果可能不同，且任何偏离边际成本定价的行为都会被至少一种标准识别为价格歧视，建议根据市场套利成本选择标准或同时报告两种结果。
There is no widely accepted definition of price discrimination with differentiated products. Either absolute price‐cost differences or percentage price‐cost markups are used as benchmarks for comparison. I show that the two criteria are qualitatively different: One may indicate price discrimination when the other does not. Moreover, anything other than marginal cost pricing will be identified as price discrimination by at least one of the two. I propose choosing a criterion based on the cost of arbitrage in the market under examination. Because this is often difficult to determine, it is advisable to always report results with both measures.