This research aims at comparing the efficiency of Islamic and conventional banks operating in the GCC countries from 2006 to 2015 for a sample of 51 conventional and 48 Islamic banks using stochastic frontier analysis and the CIR ratio. The results show that Islamic banks are less efficient in terms of cost than conventional banks, and that this result remains valid even during the 2008 crisis period and even after controlling for bank-specific variables. Regarding the determinants of bank efficiency, empirical results show that capital adequacy and size positively affect bank efficiency as measured by the stochastic frontier analysis. Results also indicate that productive assets are negatively related to efficiency as measured by the CIR ratio. This study provides new insights in terms of financial efficiency of the banking system. Findings could help Islamic and conventional banks to increase their efficiency and their performance and improve the service provided to customers.

This research empirically assesses the contribution of Islamic finance to the financial stability of banks. The empirical analysis is based on the annual data related to 103 banks (51 Islamic banks and 52 conventional banks) operating in six countries of the Gulf Cooperation Council (GCC) region during the period 2006–2015. The LADR ratio was computed and used to measure banks stability in the short term, and the Z -score was used to assess long-term stability.The results show that, overall, Islamic banks are financially more stable in the short-term but less stable in the long term than conventional banks. The comparative analysis of the financial stability determinants in the two systems shows that these determinants contribute differently to the short- and long-term financial stability of Islamic and conventional banks. This is due to the dissimilarities in the two operating principles.