Welfare States are considered key tools to provide just transitions. The hypothesis of synergy states that Social-democratic regimes are in a better position to accomplish them. While synergy has been widely theorised, its empirical verification has remained less studied and provided contradictory results. The weaknesses detected in the state-of-the-art, such as the misalignment of empirical testing and the theoretical drivers of synergy, as well as inconsistencies in the selection of variables and biases imposed by classifications in discrete timings, lead us to define an improved methodological framework. We apply the continuous observation of Ward's hierarchical clustering in squared Euclidean distances under Thorndike's criterium to twenty-three European countries between 2008 and 2016 and reject synergy after detecting that Social-democratic regimes display the best social conditions but the worst environmental performances and that society and the environment are not linked. This outcome motivates us to propose a discussion with a focus on the sustainability of economic growth and the opportunities for sustainable welfare scholarship to settle it.

福利国家被认为是提供公正过渡的关键工具。协同作用假设指出，社会民主主义政权更有能力实现它们。虽然协同作用已被广泛理论化，但其实证验证的研究仍然较少，并提供了相互矛盾的结果。在最先进技术中发现的弱点，例如经验测试和协同作用的理论驱动因素的不一致，以及变量选择的不一致和离散时间分类所施加的偏差，导致我们定义一个改进的方法框架。我们在 Thorndike 下以平方欧几里得距离连续观察 Ward 的层次聚类 s 标准在 2008 年至 2016 年间对 23 个欧洲国家进行了评估，并在发现社会民主政权表现出最好的社会条件但环境表现最差并且社会与环境没有联系后拒绝协同作用。这一结果促使我们提出讨论，重点是经济增长的可持续性以及可持续福利奖学金解决它的机会。