ABSTRACT
The aim of this study is to evaluate the Islamic banking sector with the help of financial performance criteria and to reveal whether the sector is sustainable or not. The sustainability analysis uses the latest unit root tests that take into account Fourier expansions. The study uses unit root tests, which are generally used to analyze the sustainability of public debt, with updated versions that differ from the literature and with the help of financial performance indicators of the banking sector for sustainability analysis. The study uses the data of the Islamic banking sector operating in the member countries of the Gulf Cooperation Council (GCC) for the 4th quarter of 2013 and the 2nd quarter of 2022. The quarterly data of “ROA, ROE and Net Profit Margin” are considered as financial performance indicators for sustainability analysis. Although the results of the empirical analysis show different results for each of the financial indicators of Islamic banking in the analyzed countries, in general it shows that the Islamic banking sector operating in all GCC countries except the UAE is sustainable in terms of the financial indicators used in at least one category. These results show that the development of Islamic banking is real and promising for the future. Therefore, the development of projects that contribute to the development of the Islamic financial sector and the support of this sector is an important responsibility for the relevant parties. It is expected that these results will provide important signals to the policymakers of the respective countries and contribute to the healthy development of the Islamic banking sector.