基于TVP-VAR-SV模型的能繁母猪时变供给反应研究

探求能繁母猪供给波动的原因对实现生猪稳定保供的政策目标具有重大意义。为此，本文构建能繁母猪供给反应模型，应用TVP-VAR-SV方法研究能繁母猪供给反应的时变特征。实证结果表明：短期生猪和猪仔价格（活鸡价格）冲击对能繁母猪存栏量具有显著的正向（负向）影响，且生猪价格冲击影响效应最大；玉米价格冲击是能繁母猪存栏量短期波动的原因，而生猪疫情和经济政策不确定性冲击是能繁母猪存栏量中长期波动的主要原因，该结论与真实经济周期理论相符；生猪疫情（经济政策不确定性）冲击对能繁母猪存栏量的负向（正向）影响程度较大，且生猪疫情和经济政策不确定性水平较高时，会对能繁母猪存栏量产生更大的冲击。建议提升养殖户的生猪疫情防范和应对能力；降低经济政策不确定性水平，提升养殖户应对经济政策不确定性冲击的能力；充分应用保险和期货等经济手段稳定玉米和生猪价格，采用多种方式降低玉米价格、生猪疫情、经济政策不确定性等冲击对能繁母猪存栏量的影响。

Time-varying supply response of feeding sows based on the TVP-VAR-SV model

It is of great practical significance for the explanation of the supply volatility of feeding sows to realize the policy goal of stable hog supply. Applying the TVP-VAR-SV model, this paper studied the time-varying characteristics of the feeding sows supply response. Empirical results show that the short-term price shocks of hog and piglet (broiler) have significant positive (negative) impacts on feeding sows, and the impact of hog price shock is the largest. Secondly, the corn price is the reason for the short-term supply volatility of feeding sows, while hog epidemic and economic policy uncertainty are the main reasons for the medium-term and long-term supply volatility of feeding sows, which is consistent with the Real Economic Cycle Theory. In addition, the hog epidemic (economic policy uncertainty) has bigger and longer negative (positive) impacts on feeding sows, and higher hog epidemic and economic policy uncertainty have greater impacts on the feeding sows. Finally, to reduce the impacts of corn price, hog epidemic and economic policy uncertainty on the feeding sows, this paper provides the following suggestions: improving the ability to prevent and cope with the hog epidemic, reducing the economic policy uncertainty, and enhancing the capacity of dealing with the impact of economic policy uncertainty. Additionally, making full use of economic means such as insurance and futures to stabilize corn and hog prices is also important.