Most existing estimates of the environmental Kuznets curve (EKC) for sulfur
, which use samples of mainly high-income countries, indicate a maximum emi
ssions turning point at middle to lower high-income levels of GDP per capit
a. We use a larger and more globally representative sample than previous su
lfur EKC studies. We find that sulfur emissions per capita are a monotonic
function of income per capita when we use a global sample and an inverted-U
shape function of income when we use a sample of high-income countries. A
model estimated in first differences results in a monotonic EKC when estima
ted with both high-income and global samples. Reductions in emissions are t
ime-related rather than income-related. (C) 2000 Academic Press.