Two-Factor DEA Modeling and Clustering of Homogeneous Firms.

The paper presents a model for clustering homogeneous firms according to their operation efficiency over a certain time period. The firm efficiency is studied by the Data Envelopment Analysis (DEA) methodology, which is based on solving optimization problems and permits one to compare firms taking into account many factors of their operation. At the second step of the analysis, the time series of firm efficiency estimators obtained by DEA modeling are used to cluster firms and find stable partitions of the set of firms. [ABSTRACT FROM AUTHOR]