Growitsch, Christian; Jamasb, Tooraj; Wetzel, Heike - In: Energy Economics 34 (2012) 2, pp. 542-548
Since the 1990s, efficiency and benchmarking analysis has increasingly been used in network utilities research and regulation. A recurrent concern is the effect of observable environmental factors that are beyond the influence of firms and unobserved factors that are not identifiable on measured...