为分析基本农田保护政策对耕地保护的效果,论文把目标分解为两个问题。一是基本农田保护政策的实施是否对耕地流失面积的减少产生了影响;二是如果有显著影响,效果有多大,即因基本农田保护政策的实施。耕地流失面积减少了多少。论文收集了2004—2007年的省级面版数据,分别采用了固定效成模型、随机效应和混合OLS模型加以估计,固定效应和随机效应检验结果表明,固定效应和随机效应模型均不优子混合0IS模型。在模型估计结果的基础上,论文分析了基本农田保护政策对耕地流失的影响,并计算了基本农田保护政策的耕地保护效果。分析表明:①在2004—2007年期间。基本农田保护政策的实施对于减少耕地流失面积产生了显著影响,基本农田保护率每提高1%,每省每年平均耕地流失面积约能减少364.4hm2;②由于基本农田保护政策的实施,2004—2007年期间,全国耕地流失面积分别减少了853445.19hm2,847724.91hm2,859559.37hm2和857961.26hm2。4年合计减少耕地流失面积3418690.73hm2,约为期间实际耕地流失面积3020769.49hm2的1.13倍。
The purpose of this study aimed to assess the effects of basic farmland protection policy on the decrease of arable land. The question about this is defined as whether basic farmland protection policy affected loss of arable land, and if so, how much. Methods of fixed effects model, random effects model and pooled OLS model were employed. The province-level panel data from 2004 to 2007 was collected and used in this research, and the fixed effects model, random effects model and pooled OLS model'were applied to estimate the equations. The testing of fixed-effects and random-effects showed that pooled regression model is a good choice. The effectiveness of basic farmland protection policy on the decrease of arable land was evaluated based on the statistical significance of variable about basic farmland protection policy and by computing estimated decreased areas of arable land with and without farmland protection policy in effect. The result shows that the decreased area of arable land reduced about 364.4 hm2 with a 1% increment of basic farmland protection rate. The loss of arable land respectively decreased 853 445.19 hm2, 847 724.91 hm2 ,859 559.37 hm2 and 857 961.26 hm2 from 2004 to 2007 due to the basic farmland protection policy. The sum of the decreased arable land loss was 3 418 690. 73 hm2 in the period from 2004 to 2007, which is 1.13 times as actual farmland loss of 3 020 769.49 hm2. It is concluded that the basic farmland protection policy has provided a measurable degree of protection to arable land.