It is interesting that the more developed regions like Shanghai
and Zhejiang have a low coordination index while less developed
provinces such as Hebei and Hainan could have a quite high coordination
level (Fig. 7(a)). It means that more developed regions
could have more pressures on long-term sustainability. Yang et al.
developed a coordinated developed index to assess regional sustainability
of all the provinces and municipalities (Yang et al.,
2014). Sun et al. (2010) developed a sustainability index built
upon a multi layer index system. In both studies, the sustainability
index was a weighted composite of economic, environmental
and social variables. Due to the overwhelming contribution of
economic performance, those developed regions (e.g., Beijing,
Guangdong, Jiangsu and Zhejiang) are more sustainable than other
less-developed areas (e.g., Hebei, Liaoning and Hainan). In contrast,
our index can help better evaluate the sustainability performance of
the developed regions like Shanghai in a set of regions. It is because
that our coordination index is not positively associated with economic
development.Instead, it measures the coordination between
economic development and environmental protection.