DUALITY AND CONTINUITY

This paper fills the one remaining lacuna in (multiple-output) duality theory by proving joint continuity (in input and output vectors) of c ost, benefit, and (input and output) distance functions. Continuity is an important property where measurement error exists, for it provides assurance that small errors of measurement (of quantities or prices) result only in small errors in concepts like minimal cost. We consider continuity not only in prices and quantities, but also in technologie s. Continuity in technologies might be more important than continuity in prices or quantities, because production technologies are almost ce rtainly measured (or estimated) with error.