【作者】 张帆；

【导师】 钟甫宁；

【作者基本信息】 南京农业大学 ， 农业经济管理， 2010， 硕士

【摘要】 科技投资是提高粮食产量的重要途径之一。近年来,我国科技投入逐年增加,但是全国粮食单产增长却一直在放缓。因为全国粮食单产是各地区加权平均的单产,所以各地区的单产增长趋势可能不都是放缓。根据科技投入的边际产出率递减规律,粮食单产在绝对量增长的同时,会出现增长速度逐渐减缓,而且不同地区的放缓会有差别,通常应当是单产高的地区增速减缓得快,单产低的地区增速减缓得慢,高中低产田的单产增长速度逐渐呈现收敛趋势,但现实中往往是单产高的地区增速依然比较快,而占全国耕地面积2／3以上的中低产田的单产增长速度依然比较慢。高中低产田的粮食单产增长趋势是对科技投资的反馈,因此,当前的科技投资方向,有没有实现科技资源的最优配置,从而有效地提高粮食产量值得探讨。目前我们国家的科技资源配置是政府主导,同时给予各地很大的自主权,而且政府又通过鼓励和奖励来影响地方能够决定的资源配置,这样会导致现实生活中科技成就的评价标准通常倾向于追求创造新纪录、赶超世界先进水平,科学家本人通常也希望获得这样的成果。因此,虽然国家需要粮食综合生产能力的提高,并为此不断加大对农业科研的经费投入,而且国家和地方都有各种各样的科技进步奖励办法,但这种鼓励和奖励高产田继续创新高的科研方向可能与“通过大幅度提高中低产田的单产来提高加权平均单产,进而全面提高粮食综合生产能力”的目标不一致。因此,文章从科技投资的反馈,即单产增长趋势是否体现出边际产出率递减规律,来判断在国家需要保持粮食持续增长,而且十分重视中低产田潜力的背景下,当前的科技资源配置是不是提高粮食产量的有效政策。既然科技投入的边际产出率递减是一个客观规律,那么如果粮食生产的目标是总产或加权平均单产的尽可能提高,科技资源应当较多地配置于提高中低产田的产量,如果确实这样,高中低产田的单产应当呈现收敛的趋势,即中低产田的单产增长速度应当相对较快,现实是否如上述所推导,可以用各地区各品种粮食单产增长速度的实际数据验证,如果实际数据不支持单产增长收敛的推导,说明科技投入的方向存在一定问题,而这方面的问题在很大程度上可以用科技成果评价体系的导向作用来说明。文章的实证分析部分,为排除地理环境和自然条件的影响,把全国的省级行政单位分成6个地区,利用《中国农村统计年鉴》1987-2009年的数据,通过验证各地区内部‘粮食单产增长度与初始单产水平是否正相关来说明科技投入是否满足边际产出率递减规律,结果表明：全国一半的地区的粮食单产增长趋势不符合科技投入边际产出率递减规律,因此没有实现科技资源的最优配置。然后,又通过国家科技奖励目录和科研项目的偏向性的具体例子佐证这种科技投资方向的产生原因,结果表明：国家科技进步奖励目录中,凡是获奖多的地区都是违背科技投入边际产出率递减规律的地区；同时,从科研项目的实验基地选择可以看出科技项目偏向于高产区和高产示范田。全文研究结果表明：科技成果评价体系的导向作用使得科技投资方向偏向于高产省,从而增长潜力不同的高中低产田的增长速度没有趋同,违背科技投入的边际产出率递减规律。该文为粮食单产增长放缓提出新的解释角度,同时指出国家期望粮食综合生产能力提高的目标和政府所使用的激励手段不一致,既然高中低产田的资源配置会影响加权平均单产的提高,那么影响资源配置方式的科技投资激励体系需要做出调整,对中低产田取得的成果给予扶持和鼓励。更多还原

【Abstract】 Technology investment is an important way to increase food production. However in recent years, although the investment for science and technology increased year by year, the national yield per unit area has been slowing down. Since the national yield per unit area is weighted average of every region, so the trend of yield per unit area of every region may not slow down.According to the law of diminishing marginal returns for science and technology investment, while the absolute volume in grain production is growing, the growth rate is indeed slowing down, and there will be differences of the slowing down in different regions, usually, regions with high yield per area should be faster slowdown in growth, regions with low yields per unit should be slower slowdown in growth, and the growth rate of different fields will show the convergence trend. However, in reality, this is often not true, growth rate remained high in areas with high yields, while the growth rate in the low-yielding fields which accounts for2/3of the country’s total land area did not grow fast. The trend of growth in different fields is reflect of scientific and technological investment, therefore, whether the current direction of scientific and technological investment achieves the optimal configuration of technological resources, thus increases food production effectively is worth exploring.At present, our scientific and technological resources are led by the government, while government gives considerable autonomy in all parts of our country, and the government can influence allocation of resources determined in every places by encouraging and rewarding them, this will lead to, in practice, evaluation criteria of scientific and technological achievements usually tends to encourage a record or to catch up with the world advanced level, and the scientists themselves also hope getting such results. Thus, while our country needs comprehensive grain production capacity, and continues to increase investment in agricultural research funding, and there are various incentives for scientific and technological progress from national and local, this research direction which is created to encourage and reward new high-yield field may be agree with enhancing the overall grain production capacity target or weighted average yield by a substantial increase in the low-yielding fields. Therefore, the article, from the feedback of the scientific and technological investment, that is whether the trend of growth of field per unit area reflects the law of diminishing marginal returns, determines whether current allocation of resources is effective polices to increase food production, in the context of our hoping to keep food production growing, and attaching great importance to the potential of low-yielding fields.Since the law of diminishing marginal returns for science and technology investment is objective, if the goal is maximizing total grain production capacity or the weighted average yields, science and technology investment should be configured to increase more in the low-yielding fields of production, if this is true, growth rate of different fields should show the convergence trend, that is growth rate in the low-yielding fields should be relatively higher. Whether the reality is derived as above, we can use the actual data of grain yield growth rate of various regions and varieties to test, if the empirical result of actual data do not support derivation of growth convergence, it indicates that there are certain problems in the direction of science and technology investment, and these problems can largely be illustrated by the guiding role of scientific and technological achievements in the evaluation system. In empirical analysis, in order to eliminate geography and natural interference, the mainland of China is divided into six regions, the article verifies whether growth rate of field per unit area has a positive correlation to the level of initial yield per unit within the region, by using data of China Rural Statistical Yearbook (1987-2009), and explains whether science and technology investment meets the law of diminishing returns, the results show that:in half of the country’s6regions, growth trends of grain yield does not meet law of diminishing marginal returns for science and technology investments, so technological resources do not achieve the optimal configuration. Then, the article analyzes the causes through catalog of the National Science and Technology Award and research projects of specific cases of biased technological progress in the direction, the results show that:in Reward of National Science and Technology Progress, the more awards a region gets, the farer it is from the law of diminishing marginal returns for science and technology investment; in the meantime, the experimental base for scientific research projects selection is biased in favor of to the high land and demonstration fields of high-yield.The full text shows that:technological achievements evaluation system guides the direction biased in favor of provinces with high growth rate, thus growth rate of different fields do not converge, costarring to the law of diminishing marginal returns for science and technology investments. This article puts forward a new interpretation for slowing grain production, noting that the goals for our expecting to improve the overall grain production capacity and incentives used by the government are inconsistent. Since the allocation of resources will affect improving the weighted average yield, then encourage of scientific and technological progress which affects resource allocation system needs adjustment, and the achievement in the low-yielding fields should be given more support and encouragement.更多还原