Measuring Technical Efficiency and Productivity Change in the Nigerian Banking Sector: A Comparison of non-parametric DEA and parametric SFA

This study estimates technical efficiency, technological change and total factor productivity change in the Nigerian banking sector for the period 2005 – 2014, which encapsulates the post consolidation era and subsequent regime of banking reforms aimed at stabilizing the sector from the effects of financial crisis. The study applies both non-parametric Data Envelopment Analysis (DEA) and parametric Stochastic Frontier Approach (SFA), using Malmquist Productivity Index, and error component production function respectively, to ascertain if any significant variation in efficiency exists on a sample of twelve banks covering over 80% of total bank assets in Nigeria. The theoretical intermediation approach is applied for selection of input and output variables for both DEA and SFA. The input variables considered are total deposits, total equity and operating expenses including staff costs, and output variables are loans and operating income, which accounts for off-balance-sheet items such as non-interest or fee-based income. Findings reveal that a high degree of changes in total factor productivity is due to technological change, above all the magnitude of mean technical efficiency and total factor productivity change in DEA decreases as banks output move towards non-interest or fee based income, also inefficiency increases along the same line in SFA. Policy makers should be concerned about arbitrariness in bank’s ability to earn fee-based income, which portends high cost of banking services in the long-run.