中国区域粮食生产优势度的演变及分析

该文采用地区粮食优势度指数，实证了1994至2005年间中国粮食生产区域格局的演变情况。结果显示，近10年来中国粮食优势省区有集中的趋势，经济最为发达的北京、上海、天津和浙江等省（市）的粮食生产优势度下降最为严重，辽宁和吉林两省上升最大；东部地区的粮食生产优势正在逐步减弱，粮食生产重心正向中部和东北地区转移。粮食生产优势的区域变动可以从种粮收益、经营规模、农业劳动力机会成本等方面进行解释，东部地区虽然粮食收益较高，但是较小的规模、较高的劳力成本、以及经济作物的相对高收益都对粮食生产产生了负面影响。由此可见，东部地区粮食生产的逐步退出是历史必然。

Changes of comparative advantages of regional grain production in China

Based on the panel data of provincial grain production in China from 1994 to 2005, the trend of Chinese provincial grain structure variation was analyzed using the index of regional grain production advantage. The study found that Chinese provincial grain production showed a centralized trend on the province level. The indexes of regional grain production advantage of the developed provinces, such as Beijing, Shanghai, Tianjin and Zhejiang, decrease seriously, in contrast with the great rises in Liaoning and Jilin provinces. From regional perspectives, the gravity centers of grain production in China are transferring from the east to the central and northeast China. The driving forces of the variations can be attributed to three factors: benefits from grain plantation, household land scale, opportunity cost of agricultural labor. Although grain returns in eastern China are higher than that of other regions, smaller scale, higher opportunity cost and benefit of industrial crops bring negative influences to grain plantation of eastern China. Thus, it is necessary that grain production in eastern China decreases progressively.