روش تحليل كارايي چند جهتي: مطالعه موردي بررسي عملكرد نظام بانكي ايران

Multi - Directional Efficiency Analysis: A case Study of Iranian Banking Industry

In very recent papers Asmild et al. (2003) and Halved et al. (2004) have suggested an alternative nonparametric frontier approach namely multi-directional inefficiency analysis (MEA) to estimate the performance efficiency. MEA has many advantages over Data Envelopment Analysis (DEA) as the standard nonparametric frontier method. This index chooses the benchmark points as the proportional improvement to maximal possible reduction in each input dimension separately rather than the benchmark selection in DEA model as the improvement in proportion to current inputs allocation. Therefore MEA could provide more reliable efficiency measures. The paper provides the first efficiency study over banking industry applying multi-directional efficiency analysis for a dataset of Iranian banking system over 2004-2007. The findings of this paper support Holvad et al. (2004) in which DEA models over-underestimate the input excesses. Moreover, measuring the sizes and directions of potential improvement for each input separately across the banks provides useful information from managerial and policy implications point of view. One of the most interesting points of these findings perhaps is that for the Iranian sampled banks, generally, labour force, on average, accounts for the largest proportion of excess costs. Thus, the labour reduction has the first priority in the path of efficiency improvement. JEL Classification: C01, C02, C12, C42 Keywords: Bank, Technical Efficiency, Tarrell Index, Potential Improvement Index, Data Envelopment Analysis, Multi-directional Efficiency Analysis