“…At the level of the top-tier supplier's own organization, the purchasing function manages the upstream supply chain, a function that scholars have only recently recognized as strategic (e.g., Gadde and Hakanson 2001;Monczka, Trent, and Handfield 2005). With CSR's emergence as a prominent topic in the SCM discipline, a number of scholars have investigated the role of purchasing in the context of a responsible, or sustainable, supply chain (e.g., Carter and Jennings 2004;Hollos, Blome, and Foerstl 2012;Leppelt, Foerstl, Reuter, and Hartmann 2011;Tate, Ellram, and Kirchoff 2010), a major area of future SCM research (Schoenherr, Modi, Benton, Carter, Choi, Larson, Leenders, Mabert, Narasimhan, and Wagner 2012). On the business practice level, Paulraj (2011) pointed to the critical role of a firm's purchasing function, which selects and manages the sub-suppliers.…”