사건연구 기법을 활용한 혼합형 기업결합 효과분석 — SKT와 하나로 간 기업결합 사례를 중심으로 —

The purpose of this research is to introduce the basic logic and analysis method of the Event Study whose applicability has been actively discussed in recent enforcement of anti-trust law and to review the applicability in economic analysis regarding real competition policy. Especially, this research also examined whether the Event Study method which was mainly applied to horizontal merger cases (mainly by using Eckbo & Stillman hypothesis) can be applied to judge anti- competitiveness in conglomerate merger cases. In order to apply a real case for this research, Korea Fair Trade Commission(KFTC)’s decision regarding SKT and Hanaro Telecom merger was post-evaluated. As a result of analysis, rather than efficiency-enhancing effect through providing combination product, it was concluded to support KFTC’s decision which predicted that competent merger will only to increase the effect of the cooperation and collusion of dominant business operators and the effect of anti-competitiveness by excluding competitive business operators in wire/wireless communication and broadcasting market. Also, as the KFTC pointed out at decision then, it was confirmed that SKT’s dominance in wireless communication market resulted from its exclusive using of 800MHz frequency.