Link recommendation algorithms contribute to shaping human relations of billions of users worldwide in social networks. To maximize relevance, they typically propose connecting users that are similar to each other. This has been found to create information silos, exacerbating the isolation suffered by vulnerable salient groups and perpetuating societal stereotypes. To mitigate these limitations, a significant body of work has been devoted to the implementation of fair link recommendation methods. However, most approaches do not question the ultimate goal of link recommendation algorithms, namely the monetization of users' engagement in intricate business models of data trade. This paper advocates for a diversification of players and purposes of social network platforms, aligned with the pursue of social justice. To illustrate this conceptual goal, we present ERA-Link, a novel link recommendation algorithm based on spectral graph theory that counteracts the systemic societal discrimination suffered by vulnerable groups by explicitly implementing affirmative action. We propose four principled evaluation measures, derived from effective resistance, to quantitatively analyze the behavior of the proposed method and compare it to three alternative approaches. Experiments with synthetic and real-world networks illustrate how ERA-Link generates better outcomes according to all evaluation measures, not only for the vulnerable group but for the whole network. In other words, ERA-Link recommends connections that mitigate the structural discrimination of a vulnerable group, improves social cohesion and increases the social capital of all network users. Furthermore, by promoting the access to a diversity of users, ERA-Link facilitates innovation opportunities.

翻译：链接推荐算法在全球社交网络中塑造着数十亿用户的人际关系。为实现最大相关性，这类算法通常建议连接彼此相似的用户。研究已发现这种现象会形成信息茧房，加剧弱势显著性群体遭受的孤立，并固化社会刻板印象。为缓解这些局限，大量研究致力于实施公平的链接推荐方法。然而多数方法并未质疑链接推荐算法的终极目标——即通过数据交易的复杂商业模式实现用户参与货币化。本文倡导社交网络平台的参与主体与目标多元化，以契合社会公正的追求。为阐释这一概念目标，我们提出ERA-Link——基于谱图理论的新型链接推荐算法，通过明确实施平权行动来抵消弱势群体遭受的系统性社会歧视。我们提出四项基于有效电阻的原则性评估指标，用于定量分析所提方法的行为特性，并与三种替代方法进行对比。在合成网络和真实网络上的实验表明，ERA-Link在所有评估指标上均能产生更优结果——不仅对弱势群体而言，对整个网络亦如此。换言之，ERA-Link推荐的连接能缓解弱势群体的结构性歧视，提升社会凝聚力，并增加全体网络用户的社会资本。此外，通过促进用户接触多样性群体，ERA-Link还能创造更多创新机遇。