臺中市霧峰區農會於2015年與區內農民契作，以環境友善方式種植「益全香米」，並支付契作農民田間作業、除草與資材費用以保障農民收益，增加參與誘因。本文針對2020年間臺中市霧峰區參與契作農民進行調查，透過選擇實驗法（choice experiment, CE）分析友善環境耕作契約內容不同屬性層級，探討農民參與契約的決策偏好。本文依據過去契作研究考量個體農民和農場特徵的「農民因素」（farmer factors）（Falconer, 2000）的基礎，探討「方案因素」（scheme factors）」對契作的影響，進一步了解影響農民參與契作意願的因素。結果顯示不同的方案條件確實會影響是否參與契約的決策。「除草基金提撥」、「栽培管理統一作業」、「品質獎勵」與「基本收穫量保證和價格保障」依序影響區內農民參與契作決策的意願。依此，原來的合約下農會收購契約農民每百台斤的濕穀除了基本費1,702.5元外，另須負擔田間管理成本，共計1,960.7元。本研究所設定的最適新合約下，農民則願意放棄的稻穀收購價格來換取契約中所偏好的屬性內容的總價值，推論出願受價格（willingness to accept, WTA）為每百台斤濕穀1,686元。農民雖需負擔有機肥料、防治資材與工資等田間管理成本，但可以得到除草基金、品質獎勵加價以及超過保障產量的收入，彌補其增加的田間管理支出；而農會也減少了以上相關的支出。顯示新方案對農民和農會皆有利，不僅可以提升契作農民的管理，提升稻穀的產量和品質，也能夠顯著降低農會的收購成本。相關結果也支持受訪農民的教育程度與經營規模確實會顯著影響契約的選擇態度。研究結果有助於未來政策上推動水稻友善耕作互利契作模式的參考。

In 2015, Wufeng Farmers' Association of Taichung City contracted local farmers to grow rice (Yiquan Fragrant Rice) by using environmentally friendly practices. To encourage farmers' participation, the association established a guaranteed income model in which it covered the costs of field operations, weeding, and materials. This study surveyed participating farmers in 2020. Using the choice experiment method, we analyzed the attribute levels associated with the content of the aforementioned contract. On the basis of extant contract research, we first established “farmer factors” affecting individual operators (Falconer, 2000) to explore the impact of “program factors” on farmers' concerns about and willingness to participate in the contract. Our results revealed that program factors influenced contracting decisions. In order of decreasing importance, weeding fund allocation, unified cultivation management, quality-based incentives, and basic harvest and price guarantees affected the farmers' willingness to participate in the contract. The original contract stated that the association would pay the farmers NT$1,702.5 per 60 kg of wet grain, on average, and must shoulder NT$258.2 in field management costs. Thus, the association incurred a total cost of approximately NT$1,960.7 per 60 kg of wet grain. However, according to a new contract, the farmers were willing to accept a lower rice purchase price in exchange for the total value of their preferred attributes specified in the contract. Specifically, the farmers were willing to accept a price of NT$1,686 per 60 kg of wet grain, although they had to pay field management costs such as those of organic fertilizers, materials, and wages. Because contract farmers can obtain weeding funds, quality-based incentives, and guaranteed yield income to compensate for their increased field management expenses, the farmers' association excluded the costs associated with these items to reduce its expenditure. Accordingly, the new contract was beneficial to the farmers and the farmers' association. The new contract not only encouraged the field management of contracted farmers and improved the yield and quality of rice harvested but also substantially reduced the operating costs of the farmers' association. Moreover, the education level and scale of operation of the interviewed farmers significantly affected their choices regarding the contract. Our results can serve as a reference for future policies promoting mutually beneficial contract models for environmentally friendly rice farming.