Is there an environmental Kuznets curve for sulfur?

Most existing estimates of the environmental Kuznets curve (EKC) for sulfur, which use samples of mainly high-income countries, indicate a maximum emissions turning point at middle to lower high-income levels of GDP per capita. We use a larger and more globally representative sample than previous sulfur 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 estimated with both high-income and global samples. Reductions in emissions are time-related rather than income-related.