中文摘要：

考虑到当前世界气候变化大背景下各国政府对碳汇的重视，本文基于碳汇效益内部化和农户与政府行为的相关假设，设计了一个决定最优退耕还林补贴标准的框架，以实现社会效益的最大化。本研究首先建立了碳汇效益函数，并将其纳入土地期望收益模型，计算出社会效用最大化条件下的林木最优轮伐期；同时，将造林补贴纳入农户退耕还林决策模型之中，探索激励林农在最优轮伐期内不砍伐条件下。使政府财政支出净现值最小的退耕还林补贴标准；最后用黄土高原常见的退耕树种刺槐为例进行实证模拟。实证结果表明：黄土高原区的最佳退耕还林补贴年限为16年。补贴标准的原则是每年给予退耕补贴3985．93元／hm^2，这说明了现有的退耕还林年限还是合理的。但其实际补贴额度则低于研究中的最优补贴额度。说明现有的退耕还林政策对手农户的激励作用有限。因此，建议政府可以适当提高黄土高原区的补贴标准，这样从考虑碳汇效益的角度出发，可以同时实现农户、政府与社会的三方共赢。

英文摘要：

Considering the significance of carbon sequestration emphasized by governments in the context of global climate change, this paper is designed to determine the optimal subsidy for the Sloping Land Conversion Program （SLCP） that achieves the best social benefit, on the basis of the internalization of carbon sequestration benefits and certain assumptions of households＇ and governments＇ behaviors. Firstly, a carbon sequestration benefit function is simulated in this paper and added to the land-expected value model to calculate the optimal rotation of forests under the maximal social utility. Meanwhile, subsidy is added to the households＇ decision model of participating in SLCP to determine the very subsidy, which minimizes the NPV of financial expenditure, given households keeping forests during the optimal rotation. Finally, acacia as the main SLCP tree planted on Loess Plateau is chosen as an example to empirically simulate the research framework. The results are that the optimal subsidy of Loess Plateau is 3 985.93 yuan/hm^2 ·a, and the optimal SLCP subsidy period is 16 consecutive years. They show that the existing SLCP subsidy period on Loess Plateau is rational while the subsidy is less than the optimal subsidy, so the incentive to households is limited. Thus, it is suggested that the government should increase the subsidy in Loess Plateau region, which can realize the win-win-win situation among households, governments, and the society based on carbon sequestration benefit.