Shared Policy Commitments in the Buyer Ego‐Network and Buyer Financial Performance: A Multiplex Network Perspective

ABSTRACT Public commitments to sustainability policies have become common practice among buyer and supplier companies facing growing sustainability imperatives. Firms often pursue these commitments to address societal expectations and comply with institutional norms rather than to achieve efficiency, frequently endorsing them without a comprehensive assessment of their performance implications. Within the supply chain, when multiple firms commit to similar policies, alignment emerges across network members through shared policy commitments. Such shared commitments differ from traditional buyer–supplier coordinated alignment by introducing an additional layer of complexity beyond contractual dynamics, with potential performance consequences. Adopting an embeddedness perspective, the authors analyze 240 multiplex ego networks that capture both shared policy commitments and structural ties. Results show that shared policy commitments within a buyer ego‐network, between a buyer and its direct suppliers or among those suppliers, are positively associated with the focal buyer's financial performance, with each direction's association conditional on the level of the other. However, the findings also reveal a curvilinear relationship: buyer performance declines as network members' commitments become increasingly centered on the same policies. Network interconnectedness through contractual ties serves as a moderator, unlocking additional benefits of shared commitments. This study provides theoretical and practical insights for managing shared commitments in the buyer ego‐network while avoiding over‐embeddedness.