In this article the definitions of global and local returns to scale (proposed in the DEA literature) are discussed. A new variant of the definitions of local returns to scale (increasing, decreasing or constant) is proposed. Its equivalence to the three practical methods found in the literature is proved. An empirical example (based on real data from the Polish energy sector) is presented
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.