退耕还林生态补偿标准、农户行为选择及损益

The Payment of Grain to Green Project,the Behavior Choice of Peasants and Their Gains and Losses

合理的补偿标准是激励农户自愿参与退耕还林工程的关键,而现有退耕还林补偿标准的测算方式没有考虑农户机会成本和损益状况的动态变化和不确定性,激励机制有待完善。文章将实物期权理论引入农户收益测算中,通过数值模拟探讨南北不同地区收益不确定条件下成本收益等额补偿的转换边界,结果表明农户退耕的机会成本随时间和地域变动而变动,科学高效的退耕补偿标准也应随之变动。随后,根据2002-2013年相关统计数据以小麦和稻谷为代表估算南北不同地区退耕地块上退耕农户的机会成本,结合相关政策规定的初值密度和生态林认定标准以杉木和刺槐为代表估算南北不同地区造林成本,进而得到退耕还林的造林净收益,通过比较历年种植农作物和造林的净收益,表明种植农作物的净收益呈现波动上升的状态,2002-2009年期间的退耕还林净收益高于种植农作物的净收益,农户因退耕受益,2010-2013年期间的退耕还林净收益低于种植农作物的净收益,农户因退耕受损。最后,利用几何布朗运动模拟2014-2030年的退耕机会成本的可能走势并与转换边界进行比较,得到粮食产量、补偿标准与农户受损概率之间的关系,结果表明,新一轮退耕还林政策下退耕农户的受损概率随农作物产量的增加而增加,随补偿标准的增加而减小,在相同立地条件和相同补偿标准下南方地区退耕农户受损的概率更大。文章为新一轮退耕还林政策的有效实施提供了理论依据,其政策含义是在中央政府"一刀切"政策现状下,地方政府应结合地域特征和机会成本的变化制定退耕还林补偿标准,在选择退耕地块时应考虑地块的立地条件,避免宜耕地被退。

A reasonable payment motivates peasants to participate in the Grain to Green Project （GTGP） voluntarily. However, the current payment scheme requires improvement as it lacks the consideration of the dynamic changes and the uncertainty of the peasants’ opportunity cost. In this paper, we estimated the peasants’ income by employing the real option theory. The conversion boundaries of land use in southern and northern regions of China are calculated by considering the uncertainty in agricultural return. The results indicate that the farmer’ s opportunity cost varies with region and time. An efficient payment scheme should adapt to the changing opportunity cost. Thereafter, by choosing wheat and grain as the representative crop for the southern and northern China respectively, the farmer’s opportunity cost is estimated through the historical data from 2002 to 2013. The net income of afforestation in southern and northern is estimated by choosing cedar wood and locust as the representative with the intimal density given by the government regulation for GTGP. The fluctuating increase in pattern of the net income of agriculture is clear in the results. Moreover, the results show that in the period of 2002-2009, the payment from GTGP is higher than agriculture whereas, the income from agriculture is higher in the period of 2010-2013. Finally, we assume the farmer’s opportunity cost from 2014 to 2030 follows a geometric Brownian motion. Comparing the obtained opportunity cost to the conversion boundary, a statistic measure is formulated. The results indicate that the probability of the farmer suffering lost increases as the crop yield increases, and decreases with growing payment. Moreover, there is a higher chance for the farmer in southern China suffering lost under the same crop yield and payment standard. This work lay down theoretical foundation for the next round GTGP . As the central government has set a unified payment despite the difference in region and time, our results suggest that local authorities should supplement the payment to compensate the opportunity cost changes regarding region and time difference. To avoid rich land being converted, local authorities should take the land quality into consideration when choosing which land should be included in GTGP .