Unfortunately, empirical research investigating the relationship between competitive advantage and GSCM adoption is scarce. Although conceptual literature supports the proposition that GSCM leads to competitive advantage (Markley and Davis, 2007), few studies have tested this relationship. In addition, the limited quantity of empirical work in this area has yielded some conflicting results. Some research suggests that implementation of GSCM is not directly linked to measures of competitive advantage (Kim, 2011); other studies have found such a relationship to be significant (Rao and Holt, 2005; Zhu and Sarkis, 2004).