Revenue Diversification Through Non-Interest Income and Bank Performance in European Banking

This paper examines the relationship between revenue diversification, profitability, and risk in European banks, with particular emphasis on the structural break induced by the COVID-19 shock. Using quarterly supervisory data from the European Banking Authority (EBA) over the period 2016Q1–2024Q4, we distinguish between pre- and post-pandemic regimes and estimate dynamic fixed-effects models that account for unobserved heterogeneity and persistence in bank performance. The results reveal a pattern consistent with regime dependence. Descriptive (quintile-based) comparisons suggest that banks with greater reliance on non-interest income tended to report higher profitability prior to COVID-19, although data limitations prevent us from confirming this pattern in a full multivariate regression for the pre-COVID subsample. In the post-COVID period, once bank and time fixed effects, persistence, and balance-sheet characteristics are properly controlled for, revenue diversification does not exert a statistically significant effect on either profitability or earnings volatility; this result is robust across bank fixed effects only, two-way (bank and time) clustered, and one-way (bank) clustered specifications. We show that diversification is systematically associated with differences in bank size, capitalization, and lending intensity, indicating that income structure is closely linked to underlying business model characteristics. These findings suggest that the observed diversification–performance relationship largely reflects cross-sectional heterogeneity rather than a stable causal effect. Overall, the evidence indicates that revenue diversification does not provide a consistent improvement in risk-adjusted performance in European banking. Instead, performance and risk dynamics are primarily driven by balance-sheet composition and persistence. The results highlight the importance of accounting for structural heterogeneity and macroeconomic regimes when evaluating the role of non-interest income in bank performance.