Hadri, Kaddour; Guermat, Cherif; Whittaker, Julie - 2003
inefficiencies are sensitive to specification errors. One source of such errors is heteroscedasticity. This paper addresses this … issue by extending the Hadri (1999) correction for heteroscedasticity to stochastic production frontiers and to panel data …. It is argued that heteroscedasticity within an estimation can have a significant effect on results, and that correcting …