Cooper WW, KS Park and JT Pastor (1999). “Ram: A Range Adjusted Measure of Inefficiency for Use with Additive Models, and Relations to Other Models and Measures in DEA.” JPA 11(1): 5-42.
Cooper WW, KS Park and JT Pastor (1999). “Ram: A Range Adjusted Measure of Inefficiency for Use with Additive Models, and Relations to Other Models and Measures in DEA.” JPA 11(1): 5-42.