4Liu Y M, Hu W Y, Simon J N, et al. The influence of labor price change on agricultural machinery usage in Chinese agriculture[J]. Canadian Journal of Agricultural Economics, 2013, 62(2): 1-25.
5Ji Y Q, Yu X G, Zhong F N. Machinery investment decision and off- farm employment in rural China[J]. China Economic Review, 2012, 23(1): 71-80.
6Rayner A J, Keith C. Demand for farm tractors in the United States and the United Kingdom[J]. American Journal of Agricultural Economics, 1968, 50(4): 896-912.
7Hayami Y, Ruttan R. Agricultural Development: An International Perspective[M]. Baltimore and London: The John Hopkins University Press, 1980.