The power of alternative suppliers in the automotive industry-A matter of innovation?

The number of alternative suppliers is widely considered to be the most important source of power in supply chains. It is common knowledge that a buying company benefits from an increasing number of suppliers until a marginalization effect occurs. Consequently, a cost-benefit optimum must exist but has not been analyzed in a sufficiently differentiated manner in the literature. Particularly, research has not taken the variety of product groups, which is reflected by the degree of innovation, into account. Using a two-way analysis of variance, this study identifies the cost-benefit optimum for the number of suppliers and analyzes the moderating role of the degree of innovation. The analysis is based on real automotive business-to-business negotiation data. The results reveal that a cost-benefit optimum is reached at a number of three suppliers at the most. Furthermore, the impact of the number of suppliers is higher for innovative products than for more functional products. Purchasing managers can use the findings to determine the optimal size of their supplier choice set.