Internal Determinants Of Bank Profitability In South Africa: Does Bank Efficiency Matter?

Abstract

In a study conducted by Ncube (2009) to evaluate bank cost and profit efficiency, it was established that South African banks were more efficient at managing costs than generating profits. In this paper, the aim is to complement this particular work by exploring the internal determinants of bank profitability but with more focus on the impact of bank efficiency. Applying a two step-methodology framework to a panel of four small banks and four large banks for the period 2005-2011, total factor productivity efficiency (TFPE) scores were generated using the DEA methodology. Within the first stage, the intermediation approach was followed in which bank inputs included total operating expenses, labour, fixed assets, and total deposits while interest income, non-interest income and gross loans were considered as output variables. Each bank`s efficiency score for each of the periods was then evaluated based on its distance from the constructed efficiency frontier. In the second stage analysis, the Generalised Least Squares Fixed Effects Model was then performed to examine the impact of TFPE among other internal determinant factors on bank profitability indicators, specifically return on average assets (ROAA) and net interest margin (NIM). The obtained empirical findings showed that high total factor productivity efficiency and capital adequacy lead to higher profitability, while high cost inefficiency, diversification activities, large bank size, and high credit risk leads to lower profitability. Of great importance was that both models confirmed the positive role of attaining efficiency as an important driver of profitability among banks.