“…Of similar importance, however, is the identification of variables (other than Z), which may have an impact on the performance of management. In the relevant literature, this goal has been pursued using a variety of approaches ranging from simple linear regression models to non-parametric testing (for example, Wang et al, 2006;Latruffe et al, 2009;Nwachukwu et al, 2011;Shyu and Chiang, 2012). As there is no unified theoretical framework to guide selection, the variables with a potential influence on managerial efficiency have been chosen on the basis of past experience, intuition and data availability.…”