畜禽禁养区政策降低了中国生猪产能吗——基于县域面板数据的实证分析

Does the Livestock and Poultry Restricted Zone Policy Reduced China’s Pig Production Capacity?

本研究以波特假说为理论基础,创新性的将跨期选择思想引入环境规制与产业绩效的分析框架,并将畜禽禁养区政策带来的经济效应划分为短期挤出效应和长期补偿效应,以综合考察畜禽禁养区政策对于中国生猪产能的影响以及动态过程。进一步结合2006—2017年673个县的面板数据,运用双重差分(DID)法对上述研究进行了实证检验,研究发现:畜禽禁养区政策对中国生猪产能的平均处理效应呈现显著的负向影响,并且这一结果具有稳健性。运用事件研究法对政策实施效果进行逐年分解发现,畜禽禁养区政策实施的第二年、第三年显著降低了生猪产能,从第四年开始对生猪产能产生了显著的正向影响,这也为波特假说在畜禽业的成立提供经验证据;机制分析的结果表明,畜禽禁养区政策主要通过短期的成本效应对生猪产能造成不利影响,从长期来看,畜禽禁养区政策通过促进生产效率提高和培育规模养殖主体两条路径提高了生猪产能;拓展性分析讨论了畜禁养区政策的地区差异,研究发现在生猪养殖的重点发展区、约束发展区的畜禽禁养区政策均对生猪产能产生了显著的抑制作用,适度发展区的畜禽禁养区政策对生猪产能没有显示出统计水平上的显著性,但畜禽禁养区政策显著提高了潜力增长区的生猪产能。

Based on Porter’s hypothesis,this study innovatively introduces the idea of intertemporal selection into the analysis framework of environmental regulation and industrial performance,and divides the economic effects of livestock and poultry prohibition zone policy into short-term crowding out effect and long-term compensation effect,so as to comprehensively investigate the impact and dynamic process of livestock and poultry prohibition zone policy on China’s pig production capacity.Further,combined with the panel data of 673 counties from 2006 to 2017,this paper conducts a robust empirical test on the above research model.We find that the policy of livestock and poultry prohibition zone has a significant negative impact on the average treatment effect of China’s pig production capacity.After endogenous treatment and a series of robustness tests,the above results are still stable.The event research method is used to decompose the policy implementation effect year by year.It is found that the second and third year of implementation of the livestock and poultry prohibition zone policy significantly reduces the pig production capacity,and has a significant positive impact on the pig production capacity from the fourth year,which also provides the empirical evidence of Porter hypothesis in the livestock and poultry industry.The results of mechanism analysis show that the policy of livestock and poultry prohibition zone has a negative impact on pig production capacity mainly through short-term cost effect.In the long run,the policy of livestock and poultry prohibition zone improves pig production capacity by promoting the improvement of production efficiency and cultivating scale breeding body.The expansibility analysis discusses the regional differences of livestock and poultry prohibition zone policy.The policies of key development areas and restricted development areas of pig breeding have significant inhibitory effect on pig production capacity.The policy of livestock and poultry prohibition zone in moderate development zone has no statistical significance on pig production capacity,but this policy significantly improves pig production capacity in potential growth area.