Social policy research is truly interdisciplinary with academics from very different theoretical perspectives working together in fervent open-mindedness towards diverse methodological approaches. The exploration of social investment (SI) welfare provision is a clear example of this spirit of interdisciplinary engagement, having stirred up critical scholarly reception and debate over the past decade. On the one hand, some colleagues underscore the potential of SI policies to improve life chances. On the other hand, some researchers voice concerns about perverse unintended consequences of SI. The most worrying scholarly critique of SI is the conjecture that SI policies reinforce rather than alleviate inequality and poverty, because of the operation of so-called Matthew effects (MEs). Parolin and Van Lancker’s commentary on our article ‘The social investment litmus test: family formation, employment and poverty’ falls within the purview of the ME critique, with some extension to other shortcomings discussed in the literature. These criticisms certainly deserve engagement, and we are grateful to the editorial board of the Journal of European Social Policy for inviting us to do so fully. In our commentary, we commence with the multidimensionality of 21st-century welfare state provision. Subsequently, we turn to the welfare state’s carrying capacity, which we maintain needs to be taken into consideration for leveraging positive feedback mechanisms between the micro and the macro level of welfare provision. By so doing, we elaborate on the implications of our research approach for understanding MEs, with insights as to how they are exacerbated or mitigated through policy (in-)complementarities. We then discuss the importance of considering synergies between policies for an improved understanding of SI returns and possible source(s) of MEs. Finally, we turn to the misconception that capacitating SI policies and compensatory consumption-smoothing and poverty alleviation are somehow in competition with each other, and discuss the normative orientation underlying SI welfare provision.

社会政策研究是真正的跨学科，来自不同理论视角的学者以对不同方法论的热情开放态度共同努力。对社会投资 (SI) 福利提供的探索是这种跨学科参与精神的一个明显例子，在过去十年中激起了批判性的学术接受和辩论。一方面，一些同事强调 SI 政策改善生活机会的潜力。另一方面，一些研究人员对 SI 的非预期后果表示担忧。对 SI 最令人担忧的学术批评是推测 SI 政策会加强而不是减轻不平等和贫困，因为所谓的马太效应 (MEs) 的作用。Parolin 和 Van Lancker 对我们文章“社会投资试金石：家庭形成、就业和贫困”的评论属于 ME 批评的范围，对文献中讨论的其他缺点有一些扩展。这些批评当然值得参与，我们感谢欧洲社会政策杂志邀请我们充分这样做。在我们的评论中，我们从 21 世纪福利国家供给的多维性开始。随后，我们转向福利国家的承载能力，我们认为在利用福利提供的微观和宏观层面之间的正反馈机制时需要考虑这一点。通过这样做，我们详细说明了我们的研究方法对理解 ME 的影响，并深入了解它们如何通过政策（内）互补性加剧或减轻。然后，我们讨论了考虑政策之间协同作用的重要性，以便更好地了解 SI 回报和 ME 的可能来源。最后，