Medium-sized cities are increasingly affected by processes of urban fragmentation and residential segregation, despite having traditionally been perceived as more socially cohesive and territorially balanced than large metropolitan areas. Acting as functional connectors between metropolitan hubs and rural regions, these cities are particularly vulnerable to unplanned suburban growth, housing market polarization and uneven access to urban opportunities. This study develops and applies a multidimensional Urban Territorial Index (UTI) to diagnose socio-spatial inequality in medium-sized cities, using Ciudad Real (central Spain) and its functional urban area as a case study. The UTI integrates six indicators across three analytical dimensions—socioeconomic, sociodemographic and housing—through a PCA-informed weighting scheme and GIS-based spatial analysis. The index is calculated at census-tract and neighborhood scales and is validated through internal consistency checks, external comparison with a local Human Development Index (r = 0.87; p < 0.001), and qualitative robustness assessments. Results reveal a pronounced core–periphery polarization: central and strategically located neighborhoods associated with key infrastructures (university, high-speed rail station and hospital) concentrate higher income levels, educational attainment and land values, while peripheral municipalities and disadvantaged neighborhoods exhibit higher unemployment, lower housing values and greater social vulnerability. The analysis also identifies population–housing mismatches linked to suburban expansion without equivalent functional integration. Beyond the local case, the study provides a transparent and replicable methodological framework tailored to medium-sized cities, where metropolitan-scale indices often fail to capture fine-grained socio-spatial disparities. The UTI offers a practical tool for comparative analysis, temporal monitoring and evidence-based urban policy, supporting more inclusive and territorially balanced development strategies in diverse institutional and geographical contexts.

Research on the informal economy has traditionally emphasized its measurement and macroeconomic effects, focusing on structural and institutional determinants. Individual psychological factors that may help explain social tolerance toward informal practices have received far less attention. This exploratory study addresses this gap by examining how Big Five personality traits and dimensions of competitiveness are associated with two components of tolerance: the acceptance of informal behaviors, and justificatory beliefs. To this end, an ad hoc questionnaire was developed, and a cross-sectional design was implemented using a stratified sample of 339 students enrolled in Business Administration programs at a Spanish university. Multivariable models estimated these associations while adjusting for gender. The results indicate that conscientiousness and extraversion are negatively associated with both acceptance and justificatory beliefs, whereas competitive affectivity exhibits a positive and consistent association with both dimensions. Within the study sample, tolerance scores were higher among male respondents. These findings raise a hypothesis for future research: awareness campaigns may achieve greater precision when they account for psychological heterogeneity. This implication should be tested in broader and more diverse populations. Drawing on this exploratory evidence, we propose a preliminary analytical model that articulates the relationships between dispositional traits and competitiveness dimensions in relation to the two components of tolerance, providing a basis for future research. From a theoretical perspective, the proposed model offers a structured basis for longitudinal testing and future experimental designs aimed at deepening the understanding of the microfoundational mechanisms underlying the informal economy.