Musu and Lines（1995）讨论了环境质量动态方程问题,即令P为现实污染存量水平,m（P）为环境自循环过程中吸收的污染流量。假设环境的吸收能力为污染存量的减函数。换言之,污染越重,环境自净能力越差,即m′（P）<0。再假设存在一个最大的污染水平Pmax,显然,m(Pmax=0。我们定义环境质量为实际污染水平与最大污染水平之差。
The objective of this paper is to study the trends of change in direct input coefficients of China. We reconstructed a time series of input\|output tables of China with 18 sectors for 1981, 1987, 1990, 1992 and 1995 at constant prices and current prices, and the tables for developed region, middle developed region and underdevelopd region. On the basis of these tables we found seven important trends on change in China′s direct input coefficients.
GUO Ju\|e Shaanxi Institute of Finance and Economics, Xi′an 710061, China
