同问啊，楼主有有结果了没

xtfrontier fits stochastic production or cost frontier models for panel data where the disturbance term is a mixture of an inefficiency term and the idiosyncratic error.  xtfrontier can
    fit a time-invariant model, in which the inefficiency term is assumed to have a truncated-normal distribution, or a time-varying decay model, in which the inefficiency term is modeled
    as a truncated-normal random variable multiplied by a function of time.