5. Discussion
5.1. Theoretical implications, limitations and future research Observations that relationships decline over time are not new (Terawatanavong, 2007; Wang & Huff, 2007). However, previous studies do not consider the role of norms in this process except in broad terms, which has led to a range of calls for further research in this area (Berthon et al., 2003; Ott & Ivens, 2009; Palmatier et al., 2007). Similarly, research into buyer-supplier relationships tends to ignore the individual-level perspective, with this also leading to calls for further research (Wathne & Heide, 2000; Williamson, 1975, 1985). This also highlights a need to consider the interactions between inter-firm and the individual levels of analysis (Wathne & Heide, 2000; Williamson, 1975, 1985). In responding to these calls, the present study offers a suite of important contributions to theory in this area.