Abstract
Deposit banks, the most important income sources of which are interest income; technological developments, increasing competitive environment, shrinking profit margins etc. for these reasons, it tries to increase its income sources by offering different products and services in addition to its traditional banking activities. This increase in product diversity has led to an increase in fee and commission income, in other words non-interest income. The aim of the study is to determine whether the operating income is dependent on a single source by measuring the degree of diversification of income sources of deposit banks in the Turkish banking sector. The scope of the study consists of the data of the deposit banks, which are in the top 10 in terms of asset size in the Turkish banking sector, between the years 2012-2021. As a result of the analysis using the Herfindahl-Hirschman (HHI) method, it is seen that banks diversify their income sources; as a result of the Trend Analysis, it has been determined that the non-interest income shares of the banks are increasing within the operating income of the banks, but the interest incomes are increasing at higher rates.
Keywords: Interest Income, Non-Interest Income, Diversification, Herfindahl-Hirschman Index, Trend Analysis