The Effect of Scale on Productivity of Turkish Banks in the Post-Crises Period: An Application of Data Envelopment Analysis

The purpose of this paper is to investigate the productivity of Turkish Banks according to the effect of scale in the Post-Crises Period. The data used in this study covers the period from 2002:1 to 2004:3. We applied Data Envelopment Analysis (DEA), which is a non-parametric linear programming-based technique for measuring relative performance of decision-making units (DMUs). We calculated DEA as constant & variable return-to-scale based on output oriented Malmquist Index. Although the scale effect can be measured with DEA scale efficiency measurement, we used scale indicators as input variables in order to find out not only scale efficiency but also scale affect directly. We applied DEA by using financial ratios (Athanassopoulos and Ballantine, 1995; Yeh, 1996) and branch & personel number indicators. This study uses five input variables as i) branch numbers, ii) personnel number per branch, iii) share in total assets, iv) share in total loans, v) share in total deposits; and five output variables as i) net profit-losses/total assets (ROA), ii) net profit-losses/total shareholders equity (ROE), iii) net interest income/total assets, iv) net interest income/ total operating income, and v) noninterest income/total assets. We find that difference in efficiency is mainly from technical efficiency rather than scale efficiency in the post-crises period. The other finding reveals that efficiency approximate between selected banks and supporting that advantage of scale economies can be lost in Turkish banking. Overall, the results confirm that Turkish banking has U shaped Scale Efficiency on selected profitability ratios. The application of this paper based on other financial ratios with decreasing and increasing return-to-scale DEA is left to future research.