Affiliation: | 1. University of Maryland, 7998 Regents Drive, 2110 Symons Hall, College Park, MD 20742, USA;2. Antitrust Division of the US Department of Justice, 950 Pennsylvania Avenue, NW Washington, DC 20530-0001, USA;3. Renmin University of China, 59 Zhongguancun Ave., Haidian District, Beijing, 100872, China |