A Network DEA Model with Super Efficiency and Undesirable Outputs: An Application to Bank Efficiency in China

Table 2

Pooled descriptive statistics of bank efficiency measured by different models.

Model	Obs	Mean	Std. Dev.	Min.	Max.	Coefficient of variation	Number of efficient DMUs
Black box (input)	185	0.663	0.400	0.000	1.446	0.603	76
Black box (output)	185	7.177	85.060	0.389	1158.000	11.852	126
NSBM	185	0.425	0.270	0.000	1.000	0.635	12
US-NSBM overall	185	0.611	0.228	0.264	1.507	0.373	16
US-NSBM 1	185	0.752	0.186	0.361	1.199	0.247	26
US-NSBM 2	185	0.802	0.155	0.323	1.507	0.193	18

Note: US-NSBM 1 and US-NSBM 2 denote US-NSBM stage 1 and US-NSBM stage 2 respectively (the same below).