A game theory approach about a decline of the rice dealings in rice wholesale market and development of contract dealings

在大米供需关系固定的情况下，建立了以买卖双方利润最大化为目标的交易行为模型。如果没有交易伙伴的市场控制力，交易谈判能力就无法体现。当数量多的时候，压低价格的交易对卖方有利；反之，当数量少的时候，压低价格对买方有利。即使数量发生变化，在考虑买卖双方费用的固定价格成立的情况下，社会总剩余是最大的。

In the condition where the relation between supply and demand of rice is fixed, we built the dealings action model assumed to attain maximization of profits of seller and buyer.If there is no market control power from a dealings partner, dealings negotiation power cannot be demonstrated.When there is much quantity, the dealings which set up price low are advantageous to the seller, and when there is little quantity conversely, it becomes advantageous to a buyer to make price low.Even if quantity changed, when the fixed price as which the expense of the both sides of a seller and a buyer was considered was set up, it was shown clearly that the social total surplus serves as the maximum.