Aggregation of Efficiency and Productivity: From Firm to Sector and Higher Levels

Here we consider various cases where researchers are interested in measuring aggregate efficiency or productivity levels or their changes for a group of decision making units. These could be entire industry composed of individual firms, banks, hospitals, or a region composed of sub-regions or countries, or particular sub-groups of these units within a group, e.g., sub-groups of public vs. private or regulated vs. non-regulated firms, banks or hospitals within the same industry, etc. Such analysis requires solutions to the aggregation problem—some theoretically justified approaches that can connect individual measures to aggregate measures. Various solutions are offered in the literature and our goal is to try to coherently summarize at least some of them in this chapter. This material should be interesting not only for theorists but also (and perhaps more so) for applied researchers, as it provides exact formulas and intuitive explanations for various measures of group efficiency, group scale elasticity and group productivity indexes and refers to original papers for more details.