关键词: 橡胶主产区, 橡胶依赖, Pearson相关系数, Tobit模型, 自增强机制, 投入—产出结构

Abstract:

Based on panel data of 18 sample villages and 612 farming households in Xishuangbanna, Pearson correlation coefficients were used in this study to measure the degree of fit between the two stages of "input-output" structure across six years, in 2012-2014 and 2014-2018. We measured changes in farmers' rubber dependence in the main producing areas and analyzed the core influencing factors based on a Tobit model. The results are as follows. 1) Rubber dependence in the main rubber production areas is decreasing. With the reduction in rubber dependence, China's domestic rubber supply will decrease, and China's rubber import dependence will increase, posing a threat to industrial security. 2) Rubber dependence fulfills the assumption of a self-reinforcement mechanism. The degree of dependence on rubber output has a pass-through effect, indicating that rubber dependence can be regulated against the trend. Therefore, policy subsidies can be used to enhance input incentives to increase rubber dependence in this period and the next, which will effectively guarantee the scale of rubber supply. 3) Increasing returns do not necessarily lead to rubber dependence. Farmers pay more attention to anticipated future income, and raising the expected income can guarantee the willingness of farmers to grow rubber. 4) Rubber dependence is manifested as land dependence. The land has "special asset attributes" after planting rubber, and changing the planting structure demands great time and capital costs. 5) Rubber dependence is also manifested as altitude dependence. In low-altitude areas that mainly supply rubber, the time cost for farmers to adjust the scale of rubber planting is relatively small, and it is easier to destroy rubber forests. Low-altitude areas should be the focus of rubber industry policy. Rubber is an important strategic resource. Once farmers begin large-scale felling of rubber trees, the waiting period to resume production will be longer, which could easily put China's rubber industry in a passive position. Therefore, it is recommended that during the period of low rubber prices and the gradual decrease in regional rubber dependence, appropriate industrial support should be given to farmers to prevent a sudden drop in the scale of rubber supply and ensure the safety of the national rubber industry.

Key words: main rubber producing areas, rubber dependence, Pearson correlation coefficient, Tobit model, self enhancement mechanism, input-output structure