Ecological development efficiency index of tropics and subtropics in China.

This paper proposes an ecological development efficiency index (EDEI) based on comprehensive metrics to measure the ecological efficiency and human development of the tropics and subtropics in China for the 2005-2016 period. In particular, the proposed index integrates the ecological footprint into the input metrics considering resource exploitation, carbon emission, and energy infrastructures. The traditional output factor, i.e., GDP, is substituted with the human development index to evaluate the local development quality on the basis of health, education, and income. It is observed that the EDEI of the tropics and subtropics in China grew slowly before stabilizing at approximately 0.92. Moreover, as shown in the Theil index analysis, the spatial heterogeneity of the EDEI in tropics and subtropics of China is increasing significantly. The EDEI of the eastern region of China is higher than that of the central region, and the EDEI of the western region is the lowest. Finally, based on the Tobit factor model, research density and urbanization are observed to be the keys to improving the EDEI for achieving sustainable growth.