Piecewise loglinear frontier and log efficiency measures

This paper shows that the Sueyoshi and Chang [Ops. Res. Lett. 8, 205–213 (1989)] remedy for Charnes et al. [Socio-Econ. Planning Sci. 16, 223–224 (1982); Ops Res. Lett. 2, 101–103 (1983)] multiplicative (or log) efficiency measure is not unit invariant, and Banker and Maindirattaʹs [Mgmt Sci. 32, 126–135 (1986)] approach should use positive-multiplier loglinear production frontiers to evaluate decision-making units (DMUs). The paper also proposes a distance oriented efficiency measure: the distance efficiency measure, which for the case of constant output and the case of linearly homogeneous production technology is unit invariant.