The choice of aggregation does not alter previous findings, as seen in Figure 9. All four social sustainability components have correlations with GDP, poverty, and inequality that follow the same patterns as indices aggregated following an arithmetic mean.

A final robustness check explores the extent to which social sustainability components, both individually and simultaneously, are associated with the variation of national poverty that cannot be explained by income level. This is an alternative way to empirically document the associations between social sustainability and income. Specifically, we regress national poverty rates against log per capita GDP, isolate the residual of that regression and test whether that residual is statistically associated with each the social sustainability components. Results, available upon request, show that there are some statistically significant associations between social sustainability components and the poverty residual. However, these associations are neither systematic nor robust to the choice of poverty rates, namely, national poverty lines and international poverty lines at US$1.90, US$3.20 and US$5.50 (2011 PPP) per person per day.

# **5. Conclusions**

Sustainable development is impossible without all three pillars of sustainability: economic, environmental, and social. Yet despite growing awareness among policy makers, the social dimension of sustainable development has been often overlooked, poorly understood, and insufficiently analyzed. COVID-19 has raised the profile of social sustainability as the international community pledges to pursue a green, resilient, and inclusive recovery. Whether this emerging policy commitment remains aspirational or becomes a transformational paradigm in practice remains to be seen. In the meantime, more foundational work to improve our understanding of social sustainability is needed.

The complexity of social sustainability when it comes to its components, interactions and goals —contrasted, for example, with monetary poverty, fiscal and debt deficits, or greenhouse-gas emissions—has led to incomplete definitions and long lists of principles, attributes and conditions that a country, a city or a community must display to be socially sustainable. Such lists include aspects as wide-ranging as social equity, intra- and intergenerational well-being, quality of life, satisfaction of basic needs, social interactions and interconnectedness, freedom, safety, security, and access to basic infrastructure and services. Both approaches, either vague or long-winded characterizations, are unhelpful in delivering a definition that can be understood, agreed upon, and operationalized.

Instead of laboring to develop yet another definition, we construct a global database of indicators related to social sustainability from readily available data sources, covering many of the principles cited in the literature, flexibly clustered around four components, and conveniently aggregated in simple and parsimonious indices. This global database contains 71 indicators, covers 193 countries and 37 territories for the period between 2016 and 2020, and builds indices of social inclusion, resilience, social cohesion, and process legitimacy. The choice of components and the number of indicators in each of these components follows three simple criteria (being an outcome, capturing unidimensional concepts, and relying on objective data or direct vulnerable groups’ perceptions). These criteria are sometimes relaxed when serious data 23