CAN SPOT AND CONTRACT MARKETS CO-EXIST IN AGRICULTURE?
构建模型研究农户与加工商为何同时使用现货和合约市场，发现两者可在纳什均衡中共存，并分析经济因素对市场相对规模的影响。
New production technologies, consumers who are more discriminating, and the need for improved coordination are among the forces driving the move from spot markets to contracts. Some worry that this tendency will result in the disappearance of spot markets, or at least that they will become too thin to be of help for an efficient price discovery process. Other authors point to the reduction in welfare of independent producers resulting from contracting in oligopsonistic industries. While a large body of literature is available tackling the contract versus spot market decision, much less is known about the reasons that lead to procurement in both markets. This paper provides a simple model to study how fundamental economic factors influence the contracting behavior of farmers and processors. In the model, processors contract upstream with price-taking farmers. Participation in both markets arises as a Nash equilibrium for a wide range of parameterizations. Numerical methods are used to examine the effects of fundamental economic factors on the relative size of the spot and contract markets.