sustainability Editorial Urban Retail Systems: Vulnerability, Resilience and Sustainability. Introduction to the Special Issue Teresa Barata-Salgueiro * and Herculano Cachinho   Citation: Barata-Salgueiro, T.; Cachinho, H. Urban Retail Systems: Vulnerability, Resilience and Sustainability. Introduction to the Special Issue. Sustainability 2021, 13, 13639. https://doi.org/10.3390/ su132413639 Received: 6 December 2021 Accepted: 8 December 2021 Published: 10 December 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Center for Geographical Studies, Institute of Geography and Spatial Planning (IGOT), University of Lisbon, 1649-004 Lisbon, Portugal; hc@campus.ul.pt * Correspondence: tbs@campus.ul.pt Contemporary urbanization process threatens our environment, challenges the livabil- ity of cities, their ability to build localized competitive advantages, to attract investment, to create jobs and ensure the well-being of people in a sustainable development path. However, in recent years, several experiences from both communities and public policy on governance, mobility or in the supply system of goods and services can be seen as signs of change in how we are dealing with urban problems. The need for sustainable transformation of cities is reinforced by the 2030 Agenda for Sustainable Development [1], particularly Sustainable Development Goal 11, which is dedicated to making cities inclusive, safe, resilient and sustainable. It is likely that cities will be greener and healthier, built around a more sustainable paradigm, which will be characterized by compactness and polycentrism, regeneration of the built environment instead of sprawl, walkability and soft forms of mobility, new combinations of scales of activity (from physical proximity to online presence) and more intense use of digital technologies embedded across all city functions. Retailing has always played a key role in cities and in people’s relationships and quality of life. Mediating production’s conditions and consumers’ needs makes retail and consumer services dynamic activities constantly adapting to changes in supply and demand, along with innovations in technology and in the industry itself. It is possible to see changes in retail and consumer services systems as a succession of periods of growth and decline in the number and diversity of retail and services categories and business formats, of centralization in the core and decentralization toward peripheries. These waves go together with population distribution, systems of mobility and transportation, consumer values, patterns of life and industry’s organization [2], as is now generally acknowledged. In the long run, urban retail and consumer services change has offered the consumers a wider and more diversified choice at better prices. However, it has also created large imbalances in the economic structure and spatial organization of urban retail systems, besides negative environmental impacts. Some shifts challenge the economic viability of many retail concepts, jeopardize the vitality of the traditional shopping streets that makes the provision harder for some groups of consumers and puts at risk the sustainability of the cities [3,4]. With the entrance of the new millennium, one has seen rising concerns with the planet and the climate change, on the ways we are using natural resources, on globalization, over-consumption, over-travelling, over-tourism. The ideas on resilience and sustainability of the retail and services systems and urban form come to the fore, boosted by international organizations, namely the UN and EU, adding new concerns both to decision making, policy design and social behavior. Retail and consumer services change is influenced by the planning and legal tradition of each country. However, the recent evolution is deeply affected by the increasing integration of local and national economies into the global economy, as most of the texts in this Special Issue show. More than one year ago, Sustainability challenged us for publishing a Special Issue on Urban Retail Systems: Vulnerability, Resilience and Sustainability. In addition to the topics Sustainability 2021, 13, 13639. https://doi.org/10.3390/su132413639 https://www.mdpi.com/journal/sustainability