This special issue is concerned with environmental Kuznets curves (EKC) -the hypothesis that there is an ‘inverted-U’ relationship between various indicators of environmental degradation and levels of per capita income. Explanations as to why environmental degradation should first increase then decline with income have focused on a number of underlying relationships, including:

the effects of structural economic change on the use of the environment for resource inputs and to assimilate waste;

the link between the demand for environmental quality and income;

types ofenvironmental degradation and ecological processes.