African swine fever and meat prices fluctuation: An empirical study in China based on TVP-VAR model

African swine fever (ASF), a fatal disease outbroken in China in August 2018, has widely attracted social concern especially in the information era. The occurrence of ASF led to an imbalance between supply and demand in pork and other meat markets. As a result, meat prices fluctuated greatly during the past year in 2019. To measure ASF quantitatively, the internet public concern index about ASF was created using web crawler methods. The relationships between ASF and meat prices were analyzed based on time-varying parameter vector auto-regressive (TVP-VAR) model. The results showed that there were some differences in the impact size, direction and duration of ASF on the prices of pork, chicken, beef and mutton, and the characteristics of time variability and heterogeneity were obvious. At the same time, the impact of ASF on meat prices is not consistent with the trend and degree of ASF. The impulse intensity is strongly correlated with the strength and duration of ASF, and it is generally weak in the early stage and much stronger in the middle and late periods. The results indicate that macro regulations, monitoring and early-warning system, standardizing production and circulation, and the public opinion monitoring and guidance about ASF should be given more attention in future to stabilize the market expectations and to promote a smooth functioning of the livestock markets.