Abstract
This study applies 3-stage data envelopment analysis (DEA) model on a sample of 29 foreign commercial banks in Taiwan in order to measure their overall operational efficiencies. Exploring adjustments on environmental and statistical noise effects incorporated in the pure performance evaluation for input slacks to achieve true managerial efficiency. Through our research, using a three-stage DEA approach, efficiency scores can function as a more specific and precise set of criteria for true managerial efficiency. Our empirical results demonstrated that the operational efficiency values after being adjusted for external environmental factors and statistical noise tend to be higher than the non-adjusted values. Our findings can help the banking management avoid resource misallocations, enhance banking efficiency and improve banking competitiveness.