In this note we intend to prove that the uniform capital intensity assumption is a general condition for relative prices to be invariant both in models with circulating capital only and in fixed capital models irrespective of machine-depreciation schedules.

This paper proposes new inverse data envelopment analysis (DEA) models considering input and output efficiency measures for the time substitution problem. We compare our DEA model with existing models in the literature. We show that existing models in the literature overestimate the required...