Andrew L. Johnson

TL;DR: In this article, the authors measured annual shell growth rates of a 374-year-old (radiometrically confirmed) bivalve mollusk specimen of Arctica islandica (Linnaeus).

TL;DR: It is shown that DEA can be alternatively interpreted as nonparametric least-squares regression subject to shape constraints on the frontier and sign constraints on residuals, which reveals the classic parametric programming model by Aigner and Chu as a constrained special case of DEA.

TL;DR: In this article, a nonparametric variant of the corrected ordinary least-squares (COLS) method, referred to as corrected concave non-parametric least squares (C2NLS), is presented.

TL;DR: A new semi-nonparametric one-stage estimator for the coefficients of the contextual variables that directly incorporates contextual variables to the standard DEA problem is developed, and evidence from Monte Carlo simulations suggests that the new 1-DEA estimator performs systematically better than the conventional 2-DEa estimator both in deterministic and noisy scenarios.

TL;DR: This paper discusses the four most widely-used approaches to guide variable specification in DEA and analyzes efficiency contribution measure, principal component analysis, regression-based test, and bootstrapping for variable selection via Monte Carlo simulations to determine each approach's advantages and disadvantages.