Our paper firstly investigates political stability as an underlying mechanism for the phenomenon of environmental spillovers across countries. If political stability exerts a significant impact on environmental quality and it is contagious across country borders, political stability of neighboring countries would be an impetus for environmental spillovers. Taking into account structural breaks in empirical analysis, we test these hypotheses based on an annual country-level panel data set during 2002 to 2018. Utilizing the dynamic ordinary least square (DOLS) method and the panel-based Vector Error Correction (VEC) model, we demonstrate that an improvement in political stability in one country not only enhances the environmental quality of its own, but also meliorates that of its neighbors through the spillovers of political stability. Our results also withstand sensitivity checks for cross-sectional dependence in the panel. Several policy implications are provided in accordance with our findings.

本文首先研究了政治稳定作为各国环境溢出现象的潜在机制。如果政治稳定对环境质量产生重大影响，并且在各国之间具有传染性，那么邻国的政治稳定将成为环境溢出的动力。考虑到经验分析中的结构性突破，我们基于2002年至2018年的年度国家级面板数据集对这些假设进行了检验。利用动态普通最小二乘（DOLS）方法和基于面板的矢量误差校正（VEC）模型我们证明，一国政治稳定的改善不仅可以提高本国的环境质量，而且可以通过政治稳定的溢出效应改善其邻国的环境质量。我们的结果还可以承受面板横截面相关性的敏感性检查。根据我们的发现，提供了一些政策含义。