競爭法下相關市場界定方法之理論與實務—兼論雙邊市場界定之挑戰

Abstract

主管機關在競爭法案件調查之初，第一個遇到的爭議通常是相關市場的界定，而這個爭議往往也是案件審理時的焦點。本文從相關市場的理論出發，依循學理原則之脈絡，逐項討論各種相關市場界定方式之內涵與優劣，包括合理替代性檢測法、需求交叉彈性檢測法、假設性獨占者檢測法、臨界損失分析法、價格相關係數法、Granger因果檢測法及運量法等，同時對各種相關市場界定方式在實務運用之發展，加以討論。 另外，針對具有雙邊消費族群、間接網路效應及價格結構非中立性等特性之雙邊市場，傳統上以單邊市場為適用對象，而建構之各種相關市場界定方式，在涉及雙邊市場案件之適用上，將會遇到各種阻礙與挑戰。本文將介紹過往文獻中針對雙邊市場之相關市場界定，曾提出之解決方法及相關討論，最後提出之本文看法與結論。

At the beginning of the competent authority’s investigation of competition cases, the relevant market definition is usually the first controversy of such case and the focus between the parties as well. This paper starts from explaining various theories of relevant market definition and follows the principles of such theories to discuss the contents of such theories item by item and to comment the pros and cons hereof, including reasonable interchangeability, cross price elasticity of demand, the hypothetical monopoly test, critical loss analysis, price correlation analysis, Granger causality test, and shipment test. This paper will also discuss the developments of the practice of the relevant market definition. In addition, regarding the two-sided markets which have the characteristics of the existence of two distinct groups of consumers, indirect network effects across groups and non-neutrality of the price structure, this paper will discuss the challenges and difficulties upon applying the traditional definitions of relevant market which were developed based on the economics of one-sided markets. This paper will introduce the relative discussions and solutions about the market definition of two-sided markets in the past relevant literature. At the end, this paper will provide the conclusions and suggestions for the market definition of two-sided market.