Do supplier perceptions of buyer fairness lead to supplier sales growth?

• A supplier's perception of a buyer's unfairness may ‘poison’ relationship quality.
• Seller's perceptions of interactional and distributive justice enhance relationship quality
• By enhancing relationship quality, the suppliers' perception of the manufacturer's fairness increases suppliers' sales growth.
• Interactional justice supersedes procedural justice in Iranian supplier–manufacturer relationships.
• Supplier's level of dependence on a manufacturer negatively moderates the effects of trust and commitment on sales growth.

Despite the growing number of studies focusing on fairness perceptions in buyer–supplier relationships, the pertinent literature mostly focuses on understanding the buyers' perceptions of fairness. In this study, we argue that sellers' perceptions of the fairness of the buyer are equally important but often overlooked. Moreover, existing research fails to provide empirical evidence for examining the long-term effects of fairness on sales growth. We address these gaps by reporting the results of a longitudinal study based on both primary data collected from automotive suppliers in 2009, and objective sales data for these suppliers from an automotive manufacturer over a three-year period after 2009. We employ a latent growth curve model, which reveals that only interactional and distributive fairness have a positive and significant effect on both trust and commitment. Our analysis further reveals that the positive effect of trust and commitment on sales growth is smaller as the supplier's level of dependency on the car manufacturer increases. When the buyer's perception of dependence is considered, these effects are reversed. Several managerial implications of these findings are provided.