中文摘要：

本文从东北地区玉米与其生产替代作物播种面积变化入手,比较分析了1978-2014年东北三省相关作物成本收益数据,进一步采用联立方程模型研究相关成本收益变动和劳动力用工约束对玉米相对播种面积的影响。结果表明,玉米单位产量上的低成本造就了其较强的生产竞争力;玉米相对播种面积具有很强的延续性,且受价格和资本投入因素影响显著,而各作物间的用工差距对玉米相对播种面积影响并不显著;玉米单产的连续提高及单产差距的拉大,对玉米相对播种面积影响在不同作物间的表现不同。为确保国内玉米稳定生产、科学调整农业结构,我国应在保障玉米最低收购价和稳定农资产品价格的基础上稳步推进玉米价格市场化改革,依托玉米育种技术提高玉米单产水平,拓展农村社会化服务内容,重塑玉米竞争优势。

英文摘要：

Based on the changes of planting areas of corn and its substitution crops from 1978 to 2014, this paper analyzes the profitability of corn production of three provinces in Northeast China, and then studies the influence of profitability and labor constraints on the relative planting area of corn by a 3SLS model. Results show that the lower unit production cost of corn contributes to its strong planting competitiveness. The relative area of corn has a strong continuity, which is impacted by the price and capital input significantly. The employment gap between different crops has no significant influence on relative corn planting area. However, with the continuous improvement and larger gap of the yield of corn, the effect of the relative corn planting area on different crops is different. In order to stabilize the domestic corn production and adjust agricultural structure scientifically, on the basis of keeping the minimum purchase price and maintaining the steady prices for agricultural products, steady reform of corn marketing mechanism is necessary. In addition, raising corn yield through corn breeding technology and developing socialized rural service can also enhance the corn competitiveness.