Determinants of bank margins in a dual banking system

Purpose The purpose of this paper is to determine of bank margins for conventional and Islamic banks in the dual banking system in Malaysia. Design/methodology/approach The study uses unbalanced panel data for 20 conventional banks and 16 Islamic banks over the period 2008-2014. The dynamic two-step GMM estimator technique introduced by Arellano and Bond (1991) is applied. Findings The results suggest that there are significant similarities with minor differences in terms of factors determining bank margins between conventional and Islamic banks in Malaysia. The margins for conventional banks are influenced by operating costs, efficiency, credit risk, degree of risk aversion, market share, size of operation, implicit interest payments and funding costs. For Islamic banks, the margin determinants are found to be operating costs, efficiency, credit risk, market share and implicit interest payments. This means that more factors influence the margins in conventional banks compared to Islamic banks. Although bank diversification activities have increased in recent years, their impact on bank margins is minimal. Practical implications The results suggest that improving operational costs, operational efficiency and credit risk management, and minimising implicit interest payments would be the best strategy to enhance the bank margins for both conventional and Islamic banks. The results also have important policy implications on the necessity to expand the size of Islamic banking in Malaysia. Originality/value There are relatively few studies concerning determinants of bank margins in emerging markets. The present study adds to the literature by presenting evidence from Malaysia, an emerging market with a dual banking system. This allows us to explore the similarities and differences between conventional and Islamic banks in Malaysia in respect of determinants of the margins.