I have a quick query regarding the stochastic frontier models. I am running a stochastic frontier model with exponential distribution in STATA (sfpanel command). Now; the readings say that you cannot use the “emean” option with exponential distribution. But in my case, not only does STATA estimate sfpanel command with “emean” option but all the results are also reasonable (have expected signs and significance). Am I missing something?

Thanks for your help in advance.