This paper studies whether the opening of the Korean retail industry in1996 has positively affected productivity and efficiency in the retail industryover time. We have found that the productivity of firms in the Korean retailindustry has improved significantly since the market opening and that marketefficiency has increased in the sense that the higher productivity firms have alarger market share. However, this productivity improvement has not beenobserved uniformly among sectors. Rather, it has been concentrated at largediscount stores, CVS, nonstore retailing, and other new venues. The newvenues and concentrated markets have been structural changes in thetraditional Korean retail market.