Abstract Based on a three-stage DEA model which is constructed by introducing three environmental factors-regional gross domestic product (GDP), fiscal expenditure and urban population, a systematic empirical study on green investment and ecological improvement in different provinces in China from 2007 to 2016 is carried out by the author of this paper. The study results show that the three-stage DEA model can adjust the impact of environmental factors and random errors on the ecological efficiency of green investment, and the estimated ecological efficiency of green investment is more scientific and reasonable. Compared with the adjusted ecological efficiency of green investment, the technical efficiency is overestimated before the adjustment, while the scale efficiency is underestimated. During 2007-2016, the average resource waste of the ecological efficiency of green investment in China reached 40.5%; the scale of green investment was uneconomic, which is the main reason of resources waste. In 2007-2016, only 55.17% of the tested provinces whose ecological efficiency of green investment were effective; the effective years of green investment ecological efficiency only accounted for 18.97% of the tested years, and most provinces and years were in the ineffective state of DEA.
2019, Vol. 36 
