Developing social capital in buyer-supplier relationships: The contingent effect of relationship-specific adaptations

Strategic buyer-supplier relationships are increasingly viewed in both the scholarly and practitioner literatures as key drivers of sustainable competitive advantage. In particular, relationship specific adaptations - the extent to which exchange members make tangible or intangible adaptations for a partner - are acknowledged as one of the central issues. Such adaptations need to be examined in context, taking into consideration the social ties that connect a firm and its suppliers. Using the lens of social capital, we examine the contingent effect of buyer and supplier relationship adaptations, and structural and cognitive capital on the development of relational capital. A sample of 163 buyer-supplier relationships within UK manufacturing firms is used to test a series of three-way moderated regressions. The data indicate that the relationship between structural and cognitive forms of social capital and the level of relational capital is moderated by the extent of the relationship adaptations made by each firm and its supplier. Contrary to expectations, the relationship between cognitive capital and relational capital was significantly negative when high levels of buyer adaptations and supplier adaptations were present, indicating a substitution effect between cognitive capital and relationship adaptations. Structural capital was found to be most strongly related to relational capital when adaptations were reciprocated by both actors. However, unilateral adaptations by either actor resulted in significantly lower levels of relational capital as structural capital increased. Implications for theory and managers are discussed, relating to the impact of different combinations of relationship-specific adaptations on social capital components in a buyer-supplier relationship. (C) 2014 Elsevier B.V. All rights reserved.