Determinan Net Interest Margin pada Bank di Indonesia

Abstract

This study aims to analyze the influence of internal bank factors on the Net Interest Margin (NIM) in the Indonesian banking sector. The independent variables in this study include Operating Expenses to Operating Income (BOPO) as a proxy for operational efficiency, Capital Adequacy Ratio (CAR) as an indicator of capitalization, Non-Performing Loans (NPL) as a proxy for credit risk, and Loan to Deposit Ratio (LDR) as a measure of intermediation function. These four variables were selected due to their theoretical and empirical relevance as key determinants affecting the performance of banks’ interest margins. This study employs a descriptive quantitative approach using panel data from 26 conventional commercial banks listed on the Indonesia Stock Exchange (IDX) during the 2013–2023 period. The sample was selected using a purposive sampling method based on the completeness and consistency of annual financial reports. The analytical technique applied is dynamic panel data regression with the First Difference–Generalized Method of Moments (FD-GMM) approach, which addresses potential endogeneity bias and captures the time dynamics of the dependent variable. Data processing was conducted using Stata 16 software. The estimation results show that the Loan to Deposit Ratio (LDR) has a significantly positive effect on Net Interest Margin (NIM), while the Capital Adequacy Ratio (CAR) has a significantly negative effect. Meanwhile, the variables BOPO and NPL do not exhibit a statistically significant impact on NIM. These findings indicate that the performance of banks' net interest margins in Indonesia is more strongly influenced by credit distribution effectiveness and capital structure rather than short-term cost efficiency or credit risk. This research is expected to provide strategic insights for bank management and regulators in formulating policies to sustainably enhance profitability.