An Alternative Treatment of Secondary Products in Input-Output Analysis: Frustration
指出ten Raa等人提出的商品技术模型会产生负系数，且这些负值并非测量误差所致，因此必须放弃从单一投入产出流中推导唯一技术系数矩阵的框架。
ten Raa, Chakraborty and Small (1984) rule out industry technology based input-output coefficients in favor of a construct based on the commodity technology model. The latter, however, produces negative coefficients. This note shows that the negatives cannot be ascribed to errors of measurement. The very framework of deriving unique technical coefficients matrices from the black-box of a single pair of input and output flows must be abandoned.