Abstract: In this paper, the changes of hog breeding efficiency from 2001 to 2016 in China before and after the implementation of hog subsidy policy were analyzed to scientifically evaluate the effectiveness of China's hog subsidy policy based on the Malmquist-Dea index and difference-in-difference approach (DID) methods. Results showed that China's large and medium scale hog-breeding scale efficiency increased slightly in general, while technical efficiency and pure technical efficiency decreased significantly, and there were differences in the total factor productivity with different hog-breeding scales. On the time series, fluctuation amplitude of technical efficiency change index was not large, but that of the total factor productivity and technological progress change index was large, and the trend of changes kept consistent. Moreover, the hog subsidy policy reduced the scale efficiency of hog breeding on the whole. Finally, further analysis found that the input of factors such as feed had significantly different impact on the different scale hog-breeding scale efficiency, which showd that the more input and the higher the regional GDP, the greater the scale efficiency of pig breeding. Hog export big county rewards and livestock standard breeding subsidy policy reduced the scale efficiency of large-scale and medium-scale hog farmers. This study showed that hog subsidy policy can hardly improve the scale efficiency of hog breeding. More efforts should be made to improve breeding technology.

Key words: hog subsidy policy, scale efficiency, Malmquist-Dea index, difference-in-difference approach