Abstract: The Ministry of Commerce and the Ministry of Agriculture of the PRC issued several files concerning advancing the development of "farmer-supermarket direct purchase" mode since 2008. The "farmer-supermarket direct purchase" supply chain can work out to supermarkets and farmers benefit, which is helpful for improving supply chain economic benefits. However, the existence of the consumers' mismatch cost and information asymmetry often complicate the decision-making process, which results from unfair distribution of supply chain profit. To solve this problem, a "farmer-supermarket direct purchase" supply chain consists of a farmer and a supermarket under asymmetric mismatch cost information is studied. The farmer produces a kind of agricultural product at a limited yield and wholesales it to the supermarket. The supermarket in turn then distribute the product to consumers.
The main work in this paper includes four parts. At first, optimal contracts are proposed and the optimal pricing strategy under full information and asymmetric information are analyzed, respectively. Second, on this basis, the effects of the mismatch cost on the equilibriums are analyzed, and consequently the farmer's profit under different wholesale price strategies is compared. Third, to address the value of information, the optimal decisions of both the farmer and supermarket are compared, and the changing of consumer surplus and social welfare under full and asymmetric information are compared. Finally, the effect of different types of consumers and asymmetric information on willingness to share information and negotiation behaviors is presented.
The results show that, the agricultural products will never be unmarketable under full information, and the contracting scheme, composed of a wholesale price and a fixed payment, can coordinate the supply chain perfectly. By solving the optimization problem, the low wholesale price strategy, the fixed wholesale price strategy and the high wholesale price strategy for farmer are presented under asymmetric information, respectively. The farmers' profit will be less due to lack of accurate information about consumer, the supermarket will get extra information rent, while the asymmetry information may not decreases the consumer surplus and the social welfare. Moreover, when the farmers' bargaining power satisfy certain conditions under the high wholesale price, the supermarket will reveal the private information voluntarily and share the agricultural products supply chain's profit with farmers.
In summary, the value of "farmer-supermarket direct purchase" supply chain under asymmetric information is investigated. Moreover, three contracting mechanisms are used to coordinating the supply chain under asymmetric information, which offers a practical and a theoretical guidance to improve the value of "farmer-supermarket direct purchase" supply chain.

Key words: farmer-supermarket direct purchase, agricultural products supply chain, asymmetric information, contracts design, consumer surplus