Measurement and Analysis of Contribution Rate for China Rice Input Factors via a Varying-Coefficient Production Function Model

To explore the internal driving force of growth rice yield per unit area in China, a model based on varying-coefficient production function is proposed this study, which comes from idea that constant elasticity parameters Cobb-Douglas can be extended to functional forms. Applying such economic analysis, one hand, dynamic contribution rate each input factor measured, and, other decomposed into net and interaction rate, thus expanding explanatory ability equation. Using model, output capital labor China’s are calculated 1978 2020, characteristics capital, generalized technological progress analyzed. Next, according composition total capital. The results show that: (1) indeed not different years. In 2020 value was between 0.3209 0.3589, with mean 0.3437, −0.1759 −0.1640, −0.1730. (2) Natural disasters do affect production. (3) When annual proportion crop increases, natural disaster (KDR) negative, whereas (LDR) positive. (4) Compared 1978, (GTPR) China 1979 shows declining trend fluctuations, (TKR) rising fluctuations (TLR) relatively stable same period. Since 2000, investment has become main for machinery, chemical fertilizer, seed pesticide four most important factors.