燃料乙醇“争粮”与“争地”问题的数理模型分析

燃料乙醇的发展是否会危及国家粮食安全是一个存在很大争议的问题。本文利用经典的数理经济模型和优化模型讨论了燃料乙醇发展引发"争粮"和"争地"的机理及其影响因素。本文认为:在短期内燃料乙醇的发展会促使粮食价格上涨进而引发"争粮"问题;从长期看,其发展有利于提高农业经济效益从而增加粮食供给量;政府只要掌控好汽油和粮食价格之间的关系,就能动态调控乙醇的发展规模,使其发展不危及国家粮食安全;在当前粮食短期内供大于求的情况下,可适当扩大粮食类燃料乙醇的生产规模。

Analysis on Mathematical Model of Competition for Grain and Land of Bio-ethanol

Whether the bio-ethanol development will threat the national grain security is a very controversial issue. By using the classical mathematical economic model and the optimization model, this paper explores the mechanism and the influencing factors of how the development of bio-ethanol cause the ＂competition for grain＂ and the ＂competition for land＂. It considers that：in the short term, the development of bio-ethanol will cause the increase of grain price and therefore triggers the ＂competition for grain＂; however, in the long run, its development will enhance the economic benefit and promote the availability of grain in the market;if the government can control well the relationship between the gasoline price and the grain price,the development scale of bio-ethanol can be regulated in a dynamic manner,thus the development of bio-ethanol will not threat the national grain securitytin the current situation of grain oversupply,China can expand moderately the production scale of bio-ethanol with grain as material.