Efficiency and Technical Change in Intertemporal Intersectoral DEA

A new procedure for the measurement of efficiency and technical change is presented, using DEA with three-dimension data (box data), pooling over sectors, regions and time. Until now, when pooling the data in panel applications it has been assumed that technology remained unchanged, so productivity change was entirely attributed to technical efficiency change. However, patterns of technology change and the decomposition into efficiency and technical change elements can be accomplished by means of restrictions on the general structure of the technology indexes. Under the assumption of non-regressive technical change, upper and lower bounds for efficiency and technical change are obtained. The new methodology is illustrated in an analysis of productivity growth in 13 manufacturing sectors in the Spanish regions from 1980 to 1992.