Les Facteurs Explicatifs d'Efficience-X Dans Les Banques Tunisiennes : Une Approche De Frontière Stochastique[Explanatory Factors of X-Efficiency In The Tunisian Banks: A Stochastic Frontier Approach]

The Tunisian banks currently operate in a very competitive environment. Long-term viability of this sector depends on its degree of efficiency. Therefore a study relating to the determinants of X-Efficiency in Tunisian banks is of major interest. For that purpose, we made recourse to an extension of the stochastic frontier approach called " Improved SFA " which assumes a parameter of truncation specific to each bank. The empirical results reveal differences in efficiency pronounced according to the size and the structure of property of the banks. The average efficiency of the small and average sizes banks is significantly more significant than that of large banks. Moreover, the public banks are relatively more efficient than the private banks. Thereafter, we analyze the internal determinants of the level of the efficiency of the Tunisian banks. Within this framework, three results deserve to be underlined. Firstly, the improvement of the level of the efficiency of the Tunisian banks is related to the managerial capacity rather than with the size of the banks. Moreover, preponderance of the activity of credit, compared to other outputs represents a source of efficiency. Secondly, there is a negative relation between the ratio equity on total asset and the efficiency of banks, which seems to indicate that those are too committed in risk activities. Thirdly, the share of the non performants loans represents a source of inefficiency, insofar as it cost of a bank increases with these types of loans, especially for the banks of large sizes.