The American electric utility data, which are frequently analyzed in the context of frontier models, can be explained by a linear model without inefficiencies. the observed maximum likelihood for this linear model is very mildly smaller than the maximum likelihood for more flexible stochastic...

Although conceptually pleasing, normal-gamma frontier models lead to difficult estimation problems. It is shown here that unless the sample size reaches several thousands of observations the shape parameter of the gamma density is hard to estimate, and that this carries over to estimates of the...

Profile methods, i.e., profile values, profile traces, profile transformations, and profile diagnostic plots, are introduced in a general setting and an interesting feature of profile transforms, the boxing property is pointed out. Profile methods are then discussed ill the frameworks of...