Abstract: The outbreak of COVID-10 Epidemic can be used as an external shock to study the role of unified market and information technology in stabilizing the prices of agricultural products. The empirical analysis based on the daily price data of 29 products in 160 wholesale markets across China with the difference-in-difference method shows that market segmentation has a significant amplification effect on the price rise of agricultural products after the occurrence of COVID-19. However, the unified market pattern of farm products circulated in the whole country has not been affected fundamentally by the epidemic, and even the small jump phenomena of market segmentation after the Spring Festival usually seen in previous years is not obvious. Further analysis shows that the improvement of informatization level of market players is one of the important reasons for this, while the gap of informatization level between regions has a negative impact on the integration of the markets. These conclusions suggest that relying on the ultra-large domestic markets and unblocking the domestic cycle and the domestic unified markets will help improve the ability of China to respond to external shocks.

Key words: price fluctuation, unified market, information technology, COVID-19 epidemic