**1. Introduction**

Over the course of recent decades and, more particularly, as a result of the financial crisis that began in 2007, there has been an increase in inequalities in income and wellbeing in the populations of many developed countries. This subject has repeatedly sparked research and international debate, giving rise to some particularly influential studies [1–5]. Spain is one of the countries in the European Union in which this rise in inequalities has been most marked [6].

The increase in inequalities that has already become evident in the last twenty years of the past century in various European countries is even more striking for appearing after decades of relative progress in matters of equity. Its emergence has been attributed to a combination of various factors: the crisis of the welfare state [7], asymmetry in the mobility of capital and labour [8], the generalization of neoliberal policies [9], the growing incompatibility between capitalist economies and democratic institutions [10] and the effects of economic globalization [4]. In this context, the COVID-19 pandemic will very likely trigger an increase in inequality from the year 2020 onwards, on both a global and a national level, for two reasons: on the one hand, the pandemic will probably give rise to an increase in global poverty [11] and, on the other hand, inequality is itself a coadjutant in the expansion of the pandemic [12].

The debate on inequalities has acquired greater visibility in recent years due to an upsurge in political attitudes and behaviours of a disruptive nature in many European cities and countries [13–19]. These attitudes and behaviours express the dissatisfaction and fears of large sections of the population about the social and urban transformations that

**Citation:** Checa, J.; Nel·lo, O. Residential Segregation and Living Conditions. An Analysis of Social Inequalities in Catalonia from Four Spatial Perspectives. *Urban Sci.* **2021**, *5*, 45. https://doi.org/10.3390/ urbansci5020045

Academic Editors: Juan Manuel Parreño Castellano, María José Piñeira-Mantiñán, Jesús Manuel González Pérez, David Plane and Simon Springer

Received: 24 February 2021 Accepted: 26 May 2021 Published: 31 May 2021

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**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/).

are occurring, as well as the policies that have accompanied them [20]. Changes in political attitudes have been apparent over the last decade in various episodes with widely varying characteristics. The most visible examples are the resistance to the imposition of austerity measures in various European countries at the high point of the financial crisis (Greece, Spain, Portugal), the emergence of the "gilets jaunes" movement in France and independence movements in other territories (Scotland, 2017; Catalonia, 2017). This unrest has been expressed electorally in a number of different ways. On the one hand, it has sparked the upsurge of newly minted political forces that challenge the traditional parties (Syriza in Greece, Podemos in Spain) and, on the other hand, it has driven the renewal of parties and movements on the far right (now represented in many national parliaments and governments of several European countries). Similarly, there have been referendums that have produced results which clearly alter the status quo (on Brexit in the United Kingdom and on constitutional reform in Italy, both in 2016).

This motley collection of phenomena displays a complexity that defies any simplification, be it the exaltation in some quarters of an upsurge in pure civic dynamism destined to advance progressive policies "from the bottom up" or the forthright condemnations emanating from other sectors, complete with labels such as "populism" and "irrationalism". In any case, these changes in political attitudes represent one of the most significant phenomena in the recent development of contemporary European societies, due to both the contradictions that they embody and the historical consequences that they could entail [18].

Various authors who have closely examined these phenomena have emphasized the importance of territorial variables in the evolution of social conflict and political discontent. Accordingly, the origins of these developments have been sought in, for example, the opposition between the "France péripherique" and the Parisian metropolis [13]; between Britain's old industrial hinterlands and the great tertiary hub of London [15,21]; between the Italian *mezzogiorno* and the better-off regions in the north and centre of the country; or between "Empty Spain" and the metropolitan areas [22]. From the spatial viewpoint, therefore, discontent could be interpreted, to a certain extent, as "the revenge of places that do not matter" [15], making it more the result of specific territories' feelings of resentment than of social inequalities in themselves.

This debate is directly linked to a perennial topic in geographical analysis: the effects of territorial diversity on a population's living conditions. As already known, there is an extensive body of research on this subject that responds to diverse approaches and themes. These include economic analyses on the factors that affect regional disparities [23–25], works on the causes and consequences of urban segregation [26–31], debates on the geography of opportunities and the neighborhood effect [32–35] and critical essays on uneven development and the demand for spatial justice [36–42].

One of the main questions addressed in this debate is precisely which factors explain, on the one hand, discrepancies in access to education, income, work or services and, on the other hand, diversity in lifestyles, beliefs and even political attitudes. Geographic tradition attributed these disparities to regional peculiarities and *genre de vie* [43], the opposition between urban and rural areas [44] or the settlements' population size [45]. However, in Europe in recent decades, extended urbanization [46,47], the spread of urban networks over the territory [48] and the relative weakening of spatial hierarchies within regions [49] have highlighted the conceptual inadequacy of those approaches and the need to address the issue from other perspectives.

The present contribution explores precisely this question, starting from the hypothesis that the key factors for explaining spatial inequalities in living conditions are not to be found in the classic territorial oppositions but rather in residential segregation. Thus, the territorial factor that would most clearly impinge upon the maintenance and reproduction of social inequalities—on the basis of income or origin, on both an urban and a regional scale—would be, above all else, the tendency of social groups to fracture. Far from being a matter of solely analytical importance, the clarification of the question is, in our opinion,

of great significance when it comes to elucidating the causes of social discontent to which we have referred above.

We define residential segregation herein as the tendency of social groups to separate from each other in urban areas according to their capacity to choose a place of residence. As is well known, this capacity depends mostly on two factors: on the one hand, disposable income and, on the other, real estate prices [29,30,38,50,51]. Under these circumstances, the most disadvantaged groups tend to concentrate in those areas where the low quality of housing, lack of amenities and/or scarcity of public services make prices relatively lower. In contrast, households that are more affluent, and thus able to choose their place of residence more easily, also tend to group together to enjoy the benefits of living among their peers and take advantage of better services. Recent studies have shown how growing income inequalities are leading to rising levels of urban socioeconomic segregation almost everywhere in the world, and more specifically in the main European cities [31,52]. In this context, one of the factors that can contribute to this increased segregation is the distribution of social housing in urban areas or, as in the case we studied, the ineffectiveness of social housing policies [53–55].

The discussion draws on research into the specific case of Catalonia in the first two decades of the 21st century. This case is particularly interesting for two reasons. First, the urbanization process has given rise to strong contrasts in this region of southern Europe: thus, more than two-thirds of the Catalan population—5 million out of 7.5 million inhabitants—reside in the metropolitan area of Barcelona, which covers barely 10% of the 32,000 sq. km that make up the region's total surface area [56]. Furthermore, in the last few decades Catalan society has experienced deep transformations that have radically altered its economic base (an ongoing transition from industry to services), modified its social structure (reduced importance of traditional social classes) and sparked strong migratory flows [57,58]. In the last ten years, moreover, these transformations have been accompanied by highly significant social and political instability [59,60].

The method used here to examine this issue involved, firstly, the selection of a series of social indicators related to the living conditions of the population resident in Catalonia. These indicators are then analysed in terms of four different spatial aggregations of the data: geographical setting, population size, the intensity of urbanization and the effect of urban segregation. It is then demonstrated that the latter variable proves most discerning when it comes to explaining the territorial factors that impinge upon people's lives. An initial processing of the data presented below was undertaken within the framework of the Report on Social Cohesion in Catalonia [60]. The methodology adopted partly follows that used in [14].

On the basis of the proposed objectives, hypothesis and methodology, this study is divided into four sections: the present introduction; a brief methodological epigraph with specifications of the data used and the type of analysis conducted; an explanation and discussion of the results obtained and, finally, a synthesis and some brief conclusions.
