但是仍然存在一个问题，即垄断或接近垄断的标准是什么。什么情况下才算是达到了垄断或接近垄断的程度？是达到50％、 70％还是90％甚至100％的市场份额才算是垄断或接近垄断？这在各国的立法和指南中都没有明确。不过加拿大的专家咨询小组对这一问题做了诠释，认为由于“垄断或接近垄断”具有差别性，因此“垄断”的概念在定性上与竞争法上的其他概念比如“实质性地减少或阻碍竞争”、“不当地减少或阻碍竞争”等并无差别。所有这些概念都通过执法和司法上的实践加以确定，“垄断”这一概念也是如此。{12}因此是否达到垄断或接近垄断的程度，首先是在衡量是否具有反竞争影响时加以考虑。如果有证据表明集中会在实质上达到这样一种程度，则排除效率抗辩的适用。
【作者简介】
应品广，单位为华东政法大学。
【参考文献】{1}Calvin S. Goldman, Q. C.，Ilene Knable Gotts, Michael E. Piaskoski, The Role of Efficiencies in Telecommunications Merger Review, 56 Fed. Comm. L. J. 87. (2003).
{2}[英]马西莫·莫塔．竞争政策—理论与实践[M]．沈国华，译，上海：上海财经大学出版社，2006:204.
{3}David Balto, The Efficiency Defense in Merger Review: Progress or Stagnation?，Antitrust, Fall 2001，at 74，76.
{4}Fabienne Ilzkovitz &. Roderick Meiklejohn, European Merger Control: Do We Need an Efficiency Defence?，5 Eur.Econ. 4 (2001)，available at:http://europa. eu. int/comm/economy<uscore>finance/publications/european<uscore>economy/2001/eers0501 <uscore>en. pdf.
{5}Calvin S. Goldman, Q. C.，Ilene Knable Gotts, Michael E. Piaskoski, The Role of Efficiencies in Telecommunications Merger Review, 56 Fed. Comm. L. J. 87. (2003).
{6}Calvin S. Goldman, Q. C.，Ilene Knable Gotts, Michael E. Piaskoski, The Role of Efficiencies in Telecommunications Merger Review, 56 Fed. Comm. L. J. 87. (2003).
{7}Dorian Swerdlow et al.，Managing Procurement Through a Merger: Capturing the Value of the Deal 2 (Booz—Allen＆Hamilton, Viewpoints on Mergers, Acquisitions, and Intergration, Aug. 2001)，available at: http://extfile. bah. com/livelink/livelink/87995/? func＝doc. Fetch&nodeid＝87995.
{8}F. M. Scherer, Some Principles for Post-Chicago Antitrust Analysis, 52 Case W. Res. L. Rev. 5，21 (2001).
{9}Thomas B. Leary, Efficiencies and Antitrust：A Story of Ongoing Evolution, Address at the Fall Forum of the ABA Section of Antitrust Law (Nov. 8，2002)，available at：http://www3.ftc. gov/speecheds/leary/efficienciesandantitrust.htm.
{10}F. M. Scherer &- David Ross, Industrial Market Structure and Economic Performance 126 (3rd ed. 1990).
{11}Report of the Advisory Panel on Efficiencies, Submitted to Sheridan Scott, Commissioner of Competition, August2005，available at: http://www. competition bureau. gc. ca/epic/site/cb-bc. nsf/en/ 01954e. html.
{12}Report of the Advisory Panel on Efficiencies, Submitted to Sheridan Scott, Commissioner of Competition, August2005，available at: http://www. competition bureau. gc. ca/epic/site/cb-be. nsf/en/01954e. html.
