Li, Ke; Lin, Boqiang - In: Energy Economics 48 (2015) C, pp. 230-241
during the period of 1997–2011 using a meta-frontier framework with the improved directional distance function (DDF). We …, it is used in a meta-frontier framework to reflect the technology heterogeneities across east, central and west China …. The results indicate that eastern China achieved the highest progress inefficiency relative to the metafrontier, followed …