The complementing role of sustainability standards in managing international and multi-tiered mineral supply chains

Supply chains (SCs) often entail suppliers beyond the focal firm's visible horizon and thus outside its awareness and management. This article conceptualizes how standards can complement the management of complex SCs to identify and manage previously unknown suppliers. Combining institutional theory and multi-tier SC management (SCM), standards and SCs are conceptualized as meta-institutional fields that can complement each other to enlarge the reach of the focal firm, reduce SC uncertainty, and ensure legitimate SC operations. This conceptualization is empirically supported with 1) a prestudy of eight interviews with large firms in the automotive industry and 2) a structured content-analysis based document analysis of twenty sustainability standards for mineral resources. The findings identify a standard's ownership, its supplier coverage, and the overlap of its requirements with institutionalized SC values, structures, and practices as critical enablers for establishing supplier compliance in complex and previously unmanaged settings, such as the upstream parts of international and multi-tiered mineral SCs. Based on these findings, focal firms can use standards to enhance the reach and power towards distant suppliers. The reviewed standards could extend their supplier coverage and focus sustainability at large to create synergies for their downstream customers. The study thus contributes a novel conceptualization of the complementing role of standards in SCs and especially beyond the visible horizon of the focal firm, refines the constructs for a standard's characterization in SCM, and provides first industry-specific empirical support for the relevance of the complementing role and how standards currently fill it.