This paper studies whether the opening of the Korean retail industry in 1996 has positively affected productivity and efficiency in the retail industry over time. We have found that the productivity of firms in the Korean retail industry has improved significantly since the market opening and that marketefficiency has increased in the sense that the higher productivity firms have a larger market share. However, this productivity improvement has not been observed uniformly among sectors. Rather, it has been concentrated at large discount stores, CVS, nonstore retailing, and other new venues. The newvenues and concentrated markets have been structural changes in the traditional Korean retail market.