农地城市流转的外部性与社会损失研究——基于武汉城市圈的实证简

我国的耕地保护形势正面临严峻挑战，征地面积逐年增加，是农地减少的主要原因。既要保证充足的建设用地支持社会经济发展，又要保证农地的质量和数量，维护生态平衡、粮食安全和农民的利益，这是一个两难的抉择。农地城市流转的决策过程应考虑各种外部性的影响，以达到社会均衡状态为目标。本文通过武汉城市圈的实证，计算农地城市流转的净外部性。结果表明，农地流转的净外部性小于农地保有的外部性，导致社会的外部性损失，并且其结果与征地的用途和周围环境有关。为了减少农地流转带来的社会损失，控制土地供给的源头，改变以需求为导向的土地供应模式；加强对失地农民的生活质量保障，严格对土地开发造成的环境污染进行控制和监管是切实可行的办法。

Research of Rural-Urban Land Conversion and Social Loss: Based on the Demonstration Study of Wuhan City Circle

The status of cultivated land resources is grim in China because of urbanization and non-agricultural developments, and the protection of rural land is now an imperative. The dilemma is providing enough land for construction without threatening ecosystem balance and food safety. Rural land conversion based on private equilibrium is far from complete and social equilibrium under external influence should be taken into account. Here we examine the Wuhan urban agglomeration, measure net external nature of land conversion and compare this to the net external of farmland possession. We found that negative externality produced by rural land conversion was greater than the decrease in positive externality caused by reduced farmland. Rural-urban land conversion has caused social loss, even if it has brought us tremendous economic profit. Residential and commercial uses improved both working and living environments, industrial and infrastructure uses led to serious environmental pollution, but the net externality was still positive in infrastructure uses because of the backward economy. The traditional mode of land supply was demand-oriented and not in the public interest and has caused environmental pollution hazards. In order to cut the social loss of decreased farmland, a change in land supply mode is practical and feasible. In addition, landless peasants should not only be allocated jobs and houses, but also maintain their living quality.