The convergence of air pollution is a key assumption in several environmental impact assessment models and one of the major ingredients for multilateral climate agreements and allocation of emission rights. In this paper, the sulphur dioxide (SO₂) emissions’ convergence among 32 OECD countries is examined using the panel stationarity test of Nazlioglu and Karul [1] that provides for smooth breaks, cross-sectional dependency and heterogeneity across the cross-sectional units. For robustness sake, we have also used a panel stationarity test that accounts for sharp breaks. Overall, the findings reveal that there is convergence of SO₂ emissions among the OECD countries. The results imply that adjusting the mean value of the relative SO₂ emissions trend path should be a key concern of the OECD nations. Moreover, the findings signify that instead of following independent paths in pollution control, the OECD countries are gravitating towards a similar standard of environmental performance. Moreover, the forecast of future relative SO₂ emission figures can be based on its past values.

空气污染的趋同是几种环境影响评估模型的关键假设，也是多边气候协定和排放权分配的主要因素之一。在本文中，使用Nazlioglu和Karul [1]的面板平稳性检验来检验32个经合组织国家之间的二氧化硫（SO ₂）排放的趋同性，该检验提供了平稳的断裂，截面依赖性和截面单元的异质性。 。为了稳健起见，我们还使用了面板平稳性测试来说明急剧的中断。总体而言，调查结果表明，经合组织国家之间存在SO ₂排放趋同。结果暗示调整相对SO ₂的平均值排放趋势之路应该是经合组织国家关注的重点。此外，调查结果表明，经合组织国家与其在污染控制方面走独立的道路，不如趋向于制定类似的环境绩效标准。此外，对未来相对SO ₂排放数字的预测可以基于其过去的值。