We discuss the nonparametric approach to profit efficiency analysis at the firm and industry levels in the absence of complete price information, and propose two new insights. First, choosing one commodity (whose price is known) as a numeraire good enables us to measure profit inefficiency in...

This paper introduces a novel approach for statistically testing group differences in shadow price estimates produced by non parametric efficiency models. The test can be applied across groups being assessed using a common efficient frontier or across groups assessed using different efficient...