具体可参看以下文献
ACF(2015)-Identification properties of recent production function estimators
OP(1996)-The Dynamics of Productivity in the Telecommunications Equipment Industry
LP(2003)-Estimating Production Functions Using Inputs to Control for Unobservables

感谢分享！

op法计算，这个是看的连玉君的分享
prodest log_y, method(op) free(log_lab1 log_lab2) proxy(log_investment) state(log_k) valueadded id(id) t(year) reps(40) poly(4)
predict op, resid

请问这个算出来是对数值，还是就是全要素生产率呢，我的数据估测出来出现了负值