【摘要】本文通过引入预期利润和农业政策等变量构建9种农产品的动态供给反应模型, 研究农作物播种面积和单位面积产量的影响因素, 并对比分析2004年农业政策调整前后农产品供给反应的差异。研究结果显示, 预期利润对农作物播种面积有显著的正向影响, 2004年农业政策调整后, 预期利润、自然风险对农产品供给的影响普遍变弱, 表明中国对农民利益的保护以及对农业基础设施投入的增加使农业生产抗灾能力增强;此外, 滞后1期播种面积和滞后1期单位面积产量对农产品供给的影响较大, 农产品供给具有刚性;灌溉面积比例、技术进步对农作物单位面积产量有显著的正向影响, 自然风险对农作物单位面积产量则有显著的负向影响。本文认为, 应充分利用预期利润与农产品供给的关系, 通过改变比较收益和农民预期, 推动农业供给侧结构性改革, 解决农产品结构性短缺的问题。此外, 加强农村基础设施建设、农业科技创新投入和抗灾防灾设施建设, 可以对农产品供给起积极作用。
【基金资助】 中国农业科学院科技创新工程 (项目编号:ASTIP-IAED-2017) 的资助;
The influence of expected profits and adjustment to agricultural policies on the supply of agricultural products in China
【Abstract】This paper constructed a dynamic supply response model for nine agricultural products by introducing variables such as expected profits and agricultural policy, studied the factors affecting the sown area and the yield per unit area of crops, and made a comparative analysis on the differences in agricultural product supply responses before and after the adjustment to agricultural policies in 2004. The results showed that the expected profits had a significantly positive impact on the sown area of crops. After the adjustment to agricultural policies in 2004, the impact of expected profits and natural risks on the supply of agricultural products generally weakened, indicating that China’s protection of farmers’ interests and increased investment in the agricultural infrastructure had enhanced the resilience of agricultural production. In addition, the sown area lagging one period and the yield per unit area lagging one period have great impacts on the supply of agricultural products, and the supply of agricultural products was rigid. The proportion of irrigated area and technological progress had significantly positive impacts on the yield per unit area of crops, and natural risks had a significantly negative impact on the yield per unit area. This paper believes that the relationship between expected profits and the agricultural product supply should be fully utilized, and the supply-side structural reform of agriculture should be promoted to change the structural shortage of agricultural products by changing comparative profits and farmers’ expectations. In addition, strengthening construction of the rural infrastructure, investment in agricultural science and technology innovation, and construction of disaster prevention and disaster prevention facilities can play a positive role in the supply of agricultural products.
【Keywords】 supply of agricultural products; expected profits; adjustment to agricultural policies; first order difference GMM estimation;
【Funds】 Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences (ASTIP-IAED-2017);
. ① Data source: Ministry of Agriculture of the People’s Republic of China (eds.) 新中国农业60年统计资料. Beijing: China Agricultural Press, (2009). [^Back]
. ② Data source: http://www.stats.gov.cn/tjsj/zxfb/201712/t20171208_1561546.html. [^Back]
. ① For example, areas in the south of the Great Wall mostly grow winter wheat, while the alternative crop is mainly rapeseed. [^Back]
. ① The data on Chongqing and Hainan were merged into those on Sichuan Province and Guangdong Province respectively. The Tibet Autonomous Region, China’s Hong Kong, China’s Macao and China’s Taiwan were not studied due to a lack of data. [^Back]
. ② National Bureau of Statistics of the People’s Republic of China (eds.) China Statistical Yearbook (2009–2016, over the years)（中国统计年鉴）. Beijing: China Statistics Press. [^Back]
. ③ Department of Rural Surveys, National Bureau of Statistics of China (eds.). China Rural Statistical Yearbook (2009–2016, over the years) (中国农村统计年鉴). Beijing: China Statistics Press. [^Back]
. ① Ministry of Agriculture of the People’s Republic of China (eds.) 新中国农业60年统计资料. Beijing: China Agricultural Press, (2009). [^Back]
. ② In this paper, the profit is deducted from the total income of each crop minus the total cost. And the household labor expense is deducted from the total cost. In the survey, it is found that farmers rarely consider household wages when calculating profits. Therefore, it is more reasonable to remove household labor costs from costs. [^Back]
. ③ The Department of Price of National Development and Reform Commission of the People’s Republic of China (eds.). National Agricultural Cost-benefit Data Assembly (1980–2016, over the years)（全国农产品成本收益资料汇编). Beijing: China Statistics Press. [^Back]
. ④ National Meteorological Information Center (http://data.cma.cn). [^Back]
. ① Since the total yield is the product of the sown area and the yield per unit area, that is, yit = AitYit, after calculating the logarithm, we get lnyit = lnAit+ lnYit. The expected profits as are taken as an example to calculate the long-term elasticity to the total yield. We calculate the partial derivatives of the expected profitsby the two sides of the above formula, and get. Then, we multiply both sides simultaneously by, and get. In other words, the long-term elasticity of expected profits to the total yield is equal to the sum of the elasticity of the sown area and that of the yield per unit area. [^Back]
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