Abstract
Several recent studies have identified inverted-U relationships between pollution and economic development. We investigate this question using a cross-national panel of data on emissions of four important air pollutants: suspended particulate matter, sulfur dioxide, oxides of nitrogen, and carbon monoxide. We find that per capita emissions of all four pollutants exhibit inverted-U relationships with per capita GDP. While this suggests that emissions will decrease in the very long run, we forecast continued rapid growth in global emissions over the next several decades.