Impact of corruption on bank soundness: the moderating impact of Shari’ah supervision

Purpose: This study aims to examine whether the soundness of Islamic banks is differently affected by corruption compared to conventional counterparts. Moreover, the Shari’ah supervisory board (SSB), as a cornerstone of Islamic banking and representing a multi-layer corporate governance model, is expected to moderate the influence of corruption on soundness for Islamic banks. Design/methodology/approach: This study considers a unique sample of 1,528 observations on 71 Islamic banks and 120 conventional banks operating in 11 emerging and developing Muslim countries over the 2010–2017 period. This study uses generalized least squares regression model and the coefficients are estimated by using random-effects estimator. In addition, to overcome a potential endogeneity concern for corruption and bank stability relationship, this study uses Two-Stage Least Squares regression instrumental variable estimator. Findings: The authors find consistent evidence that higher levels of corruption adversely impact the soundness for conventional banks, in favor of the sand the wheel hypothesis in the corruption–development nexus. However, as expected, this study finds a less negative impact of corruption on soundness of Islamic banks. Moreover, SSB moderates the relationship between corruption and soundness of Islamic banks. The findings are robust to a battery of alternative checks. Research limitations/implications: Findings of the paper regarding the detrimental impact of corruption on bank soundness justify the urgency of the anti-corruption campaigns in these countries, particularly for conventional banks. Moreover, the findings provide support for the positive contribution of SSBs to overcome the adverse effect of corruption on soundness of Islamic banks and thereby underscoring the need for enforcement and regulatory mechanism for SSBs to be more effective. Originality/value: To the best of the authors’ knowledge, this is the first study to examine the moderating impact of Shari’ah supervision on the relationship between corruption and soundness of Islamic banks.