What drives the long-term relationship between economic development and environmental quality? The role of spatial dispersion vs. agglomeration
研究提出空间效应（环境质量与集聚经济的权衡）是驱动经济发展与环境质量长期关系的新因素，理论上可形成环境库兹涅茨曲线，并分解1990-2017年美国空气污染变化验证了空间效应对一氧化碳浓度下降的潜在重要性。
The dramatic improvement in air quality in major Chinese cities in recent years has led to renewed interest in the question of whether economic development allows a country to “grow” out of its environmental problems. We shed new light on this question by identifying a new factor that can drive the long-term relationship between economic development and environmental quality , namely, a spatial effect that arises from a tradeoff between environmental quality and agglomeration economies . We show theoretically that this spatial effect can lead to an inverted U-shaped relationship between income and pollution, i.e., an environmental Kuznets curve . In addition, we decompose changes in US air pollution concentrations from 1990 to 2017 to allow for a possible spatial effect. Results point to the potential importance of a spatial effect in explaining the reductions in carbon monoxide (CO) concentrations. However, little of the change in sulfur dioxide (SO 2 ) concentrations in the US can be attributed to a potential spatial effect.