Robust nonparametric estimation of efficiency and technical change in U.S. commercial banking

This paper examines the performance of the U.S. commercial banking industry over 1984-2002. Rather than measuring performance relative to the unknown (and difficult-to-estimate) boundary of the production set, performance for a given bank is measured relative to expected maximum output among m banks using no more of each input than the given bank. This approach permits fully non-parametric estimation with vn-consistency avoiding the usual curse of dimensionality that plagues traditional non-parametric efficiency estimators. The resulting estimates are robust with respect to outliers and noise in the data.