Modelling Scale Economies with Ray-Homothetic Production Functions
提出射线齐次性作为建模规模经济的方法，允许规模经济随产出率和投入组合变化，并用实证检验其相对于齐次性和射线齐次性的价值。
Ray-homotheticity is proposed as a fruitful way of modelling scale economies. It permits scale economies to vary with the rate of output and the input mix, thus allowing ideal output to be input mix-dependent. Our empirical results illustrate the value of ray-homotheticity as a generalization of both homotheticity and ray-homogeneity. They also shed some light on the use of Wald and likelihood ratio tests for hypothesis testing in nested nonlinear models. We find instances of conflict between the two tests, and of reversal of the ordering that holds in linear models.