An fuzzy data envelopment analysis to examine the banking sector in 2007?2008 crisis period

In economies, especially in the period of crisis, efficient work is very important for banking sectors. Data envelopment analysis (DEA) is an application of linear programming that has been used to measure of efficieny. In Data Envelopment Analysis, decision making units and inputs and outputs data must be measured rightly and precisely. But especially in real world problems, it is impossible that measuring the data precisely. For such these imprecise cases, Fuzzy Data Envelopment Anaysis is recommended by using Fuzzy Theory. Thus, better efficiency scores is obtained and imprecise cases can be analysed. (Sengupta, 1992: 259-266)In this study, the conventional Data Envelopment Analysis and Fuzzy Data Envelopment Analysis will be mentioned. In application, efficiency of the 18 banks will be analysed with the technique of ?Fuzzy Data Envelopment Analysis with interval numbers? choosen among the Fuzzy Data Envelopment Analysis techniques by using the crisis period data in 2007-2008. By this analysis, effects of the crisis is examined in the Turkish banking sector. In this study, in order to make efficiency comparision homogeneously within the banks in banking sector in 2005 and 2006 deposits banks are choosen. Data of state owned banks, privately owned banks and foreign banks are taken from the book of ? Bankalarımız" which is published every year by The Banks Association of Turkey.Key Words: Data Envelopment Analysis, Fuzzy Logic, Fuzzy Data Envelopment Analysis, The Banking Sector, Financial Crisis , Malmquist TFP