As discussed above, the literature on sustainability contains a wide range of concepts and definitions of its numerous social dimensions, among which social sustainability is often considered. Commonly discussed outcomes associated with inclusion include equity, intra- and intergenerational well-being, quality of life, and the satisfaction of basic needs (see Barron et al 2023 for a recent review). Other analyses emphasize instead processes, including social interaction, interconnectedness, social integration, and participation; as well as alternative outcomes such as freedom, safety and security, and access to basic infrastructure and services as part of an integrated concept of social sustainability (see Littig and Griessler 2005; Cuthill 2010; Dempsey _et al._ 2011; Boström 2012; Purvis, Mao, and Robinson 2019; Ballet, Bazin and Mahieu, 2020).

While extensive lists of outcomes and processes help to establish the complexity and multidimensional nature of social sustainability, they are less useful in delivering a definition that can be understood, agreed upon, and operationalized. There is, however, some convergence and overlap in the literature encompassing a narrower set of outcomes and processes as discussed in the previous section and summarized in Table 1. Building on this evidence, we conducted a systematic review of available data sources to identify the dimensions and indicators widely used in empirical studies of social sustainability. We find that the construction of social exclusion metrics typically follows measurement frameworks that cluster dimensions to conceptualize one specific construct (Table 2). As such, it finds that access to markets, services and political, civic, cultural and physical spaces are grouped to conceptualize social inclusion (World Bank 2013, Das and Espinoza 2020). Absorptive, adaptive, and transformative capacities are used to conceptualize resilience (Walker _et al_ 2004, DFID 2011, IPCC 2012, Oxfam 2017).<sup>6</sup> Meanwhile empowerment, voice, agency, citizen engagement, and social accountability are grouped in one concept, namely, process legitimacy (e.g., Kabeer 1999, Fox 2007, Joshi 2008, IFPRI 2020, IDS 2020). This synthesis illustrates, both the indicators often used in terms of their global coverage, and the possibility to be unpacked by vulnerable groups and populations. This snapshot of indicators, though not comprehensive, first confirms that there are numerous indicators available from a relatively small amount of reputable data sources. Second, it shows that indicators notably vary in terms of their country coverage. This is partly a reflection of their methodologies: experts’ opinion-based sources usually have a global coverage with frequent updates, while household surveys vary in the data collected and may be realized far less frequently. Disaggregation-wise, there are also trade-offs: data based on expert opinion is national in scope and is often not designed to explore subnational, inter- and intragroup heterogeneity, including among vulnerable groups. Other sources like household surveys can unpack results across groups and location, although the extent to which those disaggregations are considered in the sample design to provide statistically significant results varies from source to source.

> 6 _Absorptive capacity_ is the capacity to take intentional protective action and adopt coping strategies to bounce back after a shock, ensuring stability as it limits the negative impact of shocks. _Adaptive capacity_ is the capacity to make intentional incremental adjustments in anticipation of or response to change, to create more flexibility in the future. _Transformative capacity_ is the capacity to make intentional change to stop or reduce the causes of risk, vulnerability and ensure a more equitable sharing of risk. It is about fundamental changes in the structural causes and aggravators of vulnerability and risk.

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