Will pollution taxes improve joint ecological and economic efficiency of thermal power industry in China? A DEA based materials balance approach

Previous studies of the efficiency of Chinese electricity industry have been limited in providing insights regarding policy implications of inherent trade-offs of economic and environmental outcomes. This study proposes a modified data envelopment analysis method combined with materials balance principle to estimate ecological and cost efficiency in the Chinese electricity industry. The economic cost and ecological impact of energy input reallocation strategies for improving efficiency are identified. The possible impacts of pollution taxes upon the levels of sulfur dioxide (SO2) emissions are assessed. Estimation results show that (i) both energy input costs and SO2 could be reduced through increasing technical efficiency. (ii) It is possible to adjust energy input mix to attain ecological efficient, and correspondingly, SO2 would reduce by 15%. (iii) The Chinese electricity industry would reduce its unit cost by 9% if optimal ecological efficiency is attained and reduce its unit pollution by 13% if optimal cost efficiency is attained, implying that there are positive ecological synergy effects associated with energy cost savings and positive economic synergy effects associated with SO2 pollution reductions. (iv) Estimated shadow costs of SO2 reduction are very high, suggesting that, in the short term, the Chinese electricity industry should pursue cost efficient point instead of ecological efficient point, since alternative abatement activities are less costly and some of the abatement cost could be further offset by energy input cost savings. (v) There would be no significant difference between the impacts of pollution discharge fees and pollution taxes on SO2 emissions levels because of the relatively low pollution tax rate.