The purpose of this study is to empirically investigate the environmental Kuznets curve (EKC) relationship between water quality and income within the European Union, considering spatial interdependences across countries. To this end, we apply a spatial econometrics framework using panel data, at the national level, for twenty EU countries across seventeen years, 1998 to 2014. Furthermore, we account for the role of human and livestock population size, institutional quality and economic openness for water quality. Results show that a significant EKC relationship is seen with an inverted N-shaped relationship between income and water quality. Water quality is decreasing in income for low income levels, increasing in income when GDP per capita for medium income levels, and deteriorating for high income levels. Eight out of twenty countries have income levels associated with a declining water quality. Spatial spillovers between countries are significant. Higher livestock density levels are associated with lower levels of water quality, while institutional quality and openness to trade are positively associated with water quality.

本研究的目的是实证研究欧盟内部水质与收入之间的环境库兹涅茨曲线 (EKC) 关系，同时考虑到各国的空间相互依赖性。为此，我们在 1998 年至 2014 年的 17 年间，使用面板数据在国家层面应用了 20 个欧盟国家的空间计量经济学框架。 此外，我们考虑了人类和牲畜人口规模、制度质量和经济开放度的作用为水质。结果表明，倒置的N具有显着的 EKC 关系收入与水质的关系。低收入水平的水质在收入中下降，中等收入水平的人均 GDP 收入增加，高收入水平的水质恶化。二十个国家中有八个的收入水平与水质下降有关。国家之间的空间溢出是显着的。较高的牲畜密度水平与较低的水质水平相关，而制度质量和贸易开放度与水质呈正相关。