The SOLA Model: A Theory-Based Approach to Social Quality and Social Sustainability

Sustainability is frequently discussed with reference to the "3-pillar" model distinguishing ecological, economic and social sustainability. However, social sustainability is treated as a residual category without adequate theoretical conceptualization. As a consequence, we find a wealth of approaches and models proposing a wide range of social indicators on individual and collective levels, both subjective and objective. While this diversity is fruitful given the range of social sciences involved and the diversity of social issues and social policies, communication between approaches and comparison of results is hindered by the lack of a common framework. The SOLA model offers an interdisciplinary, multi-level and comprehensive framework or meta-model structured by five modules (human ecology, 3 levels of social systems, ethical quality standards) which conceives social sustainability, social quality and quality of life in terms of evolving systems theory. We argue that the meta-model can facilitate systematic comparison of different approaches, bridge the gap toward natural and engineering sciences, and guide the development of social indicators. More specifically, two social indicator profiles are proposed to capture the divergence between two competing approaches to social sustainability: the social quality approach and the social capital approach. The focus in this article is on the presentation of the model and on conceptual issues of social sustainability and social quality. The model is based on an extensive review of alternative approaches. It is empirically validated in quality of life research in social and health care, and applied in on-going research on inclusive social policy.