Evaluation of power input efficiency for China's typical cities based on the DEA and SFA models

China is entering a rapid developmental stage of urbanisation characterised by tremendous economic development. However, many prominent problems have existed for a long time. Among these, problems on power efficiency should be addressed. The extended models of data envelopment analysis (DEA) and stochastic frontier analysis (SFA) were used to analyse city input-output efficiency including electric power input factor for China's typical cities. First, an index system of comprehensive evaluation about city efficiency was established, and the efficiencies of China's 23 typical cities in 2006 were evaluated based on DEA, with a focus on the rationality of electric power input. We then employed SFA to analyse the city efficiency in 2006; we further extended the data to the period between 1978 and 2006 in order to avoid data limit. The analysis results show that the relative orders of city efficiencies based on the two different models have remained more or less the same except in a few cities. Finally, some reasonable suggestions for the improvement of the city power input-output efficiency in China are proposed.