Abstract: Contract farming, as a sales model of agriculture products on the basis of forward contracts, is said to be important for solving the circulation problem and realizing industrialized management of agriculture. However, its effect has been greatly reduced due to the commonly-seen contract breaches. In the premise of contract incompleteness, this article establishes a simple single-period conversation price model to show contract breaches are caused by the fact that both production condition and market condition are unpredictable. And this model is also aimed to prove there is a lack of specific investment in agriculture products, which lowers the probability of contract implementation and additional value generated by contract trade. On the basis of that, the paper provides a new type of agriculture products contract with the character of option. Through the corresponding renegotiation, this kind of option contract can not only protect farmers from market risks like traditional contracts do, but also solve tradition ones’ inefficiency problems resulted from one-sided contract breaches. At last, this paper demonstrates that under the option contract, both farmers and assemblers will make the optimal specific investment decisions. Accordingly, the low additional value problem, which is caused by insufficient specific investment, gets solved.

Key words: contract farming, incomplete contract, option contract, specific investment

摘要： 订单农业作为一种基于远期合约的农产品销售模式,被认为是解决农产品流通困难问题并实现农业产业化经营的重要出路,但订单农业的价值由于其普遍存在的违约现象而大打折扣。本文在合约不完全性的前提下,用一个简单的单期保护价模型说明了生产条件和市场条件的不可预知性是订单农业违约的根本原因,并证明此时一定存在农产品专用性投资不足的问题。而低水平的专用性投资既降低了履约的概率,又降低了订单交易所能产生的附加值。在此基础上,本文给出了一种具有期权性质的农产品合约,并证明经过相应的再谈判程序,期权合约既可以像传统订单合约一样帮助农户规避市场风险,又可以解决传统订单下无效率的单方面毁约问题。最后,本文证明了在期权合约下,农户和农产品收购商都将作出最优水平的专用性投资,低水平专用性投资带来的低附加值问题由此得到解决。

关键词: 订单农业, 不完全合约, 期权合约, 专用性投资