npsf

Nonparametric efficiency measurement and statistical inference via DEA type estimators (see Färe, Grosskopf, and Lovell (1994) doi:10.1017/CBO9780511551710, Kneip, Simar, and Wilson (2008) doi:10.1017/S0266466608080651 and Badunenko and Mozharovskyi (2020) doi:10.1080/01605682.2019.1599778) as well as Stochastic Frontier estimators for both cross-sectional data and 1st, 2nd, and 4th generation models for panel data (see Kumbhakar and Lovell (2003) doi:10.1017/CBO9781139174411, Badunenko and Kumbhakar (2016) doi:10.1016/j.ejor.2016.04.049). The stochastic frontier estimators can handle both half-normal and truncated normal models with conditional mean and heteroskedasticity. The marginal effects of determinants can be obtained.