1. Economic Research Service -United States Department of Agriculture. Figure 4 Annual irrigated areas in China;Source,1983
2. Economic Research Service -United States Department of Agriculture;Source
3. The variable of housing investment is the dummy, which captures 1 for 1986, 1987 and 1992 and 0 for other years. The amount of housing investment increased to 85.5 per cent of farmers' total investment in 1986, 88 per cent in 1987 and 70 per cent in 1992. The sign of this variable is greater than zero, which means that it has positive impact on technical inefficiency. There are some reasons for low agricultural investment in this period. Huang (1998) claims that the main reason is the nature of land contract, which farmers do not own the land. This made them reluctant to have long -term investment. Furthermore, the equal division of land between households prevented them from economies of scale in agricultural production. There is a link between housing investment and land tenure system in China during the period;According;agricultural investment was low, but housing investment was high during the stagnation period,1983
4. Formation and estimation of stochastic frontier production function models;D J Aigner;Journal of Econometrics,1977