Drivers of Net Interest Margin in Ethiopia’s Banking Sector

Abstract

This study examines the drivers of net interest margin (NIM) in developing economies, with a particular emphasis on Ethiopian commercial banks. It adopts an explanatory research design, analyzing quantitative data from the audited financial statements of 13 banks over 13 years (2012–2024), totaling 169 observations. Both Driscoll–Kraay fixed- and random-effects standard errors were computed in RStudio (version 4.5). The primary analysis relied on Driscoll–Kraay random regression outcomes, though fixed regression results were included for robustness checks. Findings indicate that the loan-to-deposit ratio, bank size, capital adequacy, and foreign direct investment (FDI) inflows have a significant positive impact on NIM, underscoring their role in enhancing profitability and stability. Conversely, inflation significantly reduces margins, while no substantial effects were observed for operational efficiency or GDP. These insights suggest that Ethiopian banks should focus on asset growth, maintaining strong capital reserves, increasing the loan-to-deposit ratio, and attracting FDI. Policymakers are encouraged to stabilize inflation and create a conducive environment to FDI to support sectoral growth. Future research could investigate operational efficiency alongside industry-specific indexes, such as the Herfindahl–Hirschman index for loans, assets, and income, to better understand variations in NIM.