Portfolio strategies in supply contracts

Abstract

Traditionally, industrial buyers have focused on long-term contracts for many of their purchasing needs. Recently, however, some high-tech manufacturers have started looking at more flexible contracts for non-strategic components, which enables them to buy from a variety of suppliers and the spot market. We study this type of strategies in a general framework for supply contracts, in which portfolios of contracts can be analyzed and optimized. We examine a multi-period model where expected profit is optimized, and a single-period model where a mean-variance objective is considered. In addition, we investigate what the consequences of such purchasing behavior might be. For this purpose, we study the game where suppliers compete on price and flexibility for the buyer's orders. We characterize the suppliers' Nash equilibria in pure strategies and show that, when demand is log-concave, there exists one or multiple equilibria, and that in any of these, suppliers bid in clusters against other suppliers with similar technologies.