近年來政府鑑於稻穀保證價格收購制度有鼓勵增產的作用，違反關稅暨 貿易總協定(GATT)的原則，而且收購及撥舊的成本很高，故積極研議採行「價 差補貼」的支持方式，以減少對農產品市場機能的干擾，並降低操作成本。本文 分析政府將所實施的稻穀保證價格收購制度改為價差補貼制度之後，是否確實可 以避免鼓勵稻農增產?結果發現:若農家為一風險趨避者，且其相對風險趨避函數 值小於一，則價差補貼與稻穀保價收購制度皆其有增產作用，而且 「價差補貼」 制度下的最適農產量，必不小於 「最低保證利潤率」計劃收購制度下的最適農 產量。若是把目前臺灣所實施的「最低保證利潤率」計劃收購制度改成其有相同 支持價格之「價差補貼」制度，非但不能發揮避免鼓勵農民增產之效果，甚至有 可能惡化鼓勵增產的現象。不過我們發現，在此情形下實施價差補貼制度都能帶 給農家較高的福利。

　　　　　This paper examines supply responses to the planned paddy purchase program and a substitutive scheme of deficiency payment in Taiwan. It is found that, in the case where a risk-averse farmer's coefficient of relativerisk aversion is less than one, both schemes will enlarge the optimal level of his planned production. As the optimal level of production under deficiency payment is not less than that under planned paddy purchase program, it may reinforce the output-increasing effect when replacingplanned paddy purchase program with a deficiency payment scheme of thesame support price. Nevertheless we show that the farmer's welfare froma deficiency payment scheme is possibly greater than that implied by planned paddy purchase program.