*4.1. Population Growth in the 69 FUAs: Growing Diversity among Urban Areas*

4.1.1. Urban Cores versus Peripheries: Comparing Economic Crisis and Post-Crisis Phases

Figure 1 shows annual growth rates for metropolitan cores and peripheries in both periods analyzed (for the complete dataset, see Appendix A, Table A1). Very significant and outstanding differences can be observed between the two intervals. In the economic crisis phase, most Spanish FUAs lost population (white spheres). Only 23 out of the 69 FUAs analyzed gained inhabitants (blue spheres). The largest group, containing 33 cases, experienced a combination of urban core population loss and peripheral population growth. In another 18 metropolitan areas, both cores and suburban municipalities lost population. There were just 12 cases where both areas of the FUAs gained residents, and only six urban cores grew as their peripheries lost inhabitants. In sum, between 2011 and 2015, the 69 FUAs lost residents, as they had a CAGR of −0.10%, and although the population of the periphery grew by 0.31%, that of urban cores decreased by −0.44%.

**Figure 1.** Core and ring cumulative annual growth rates (CAGRs) for the 69 Spanish FUAs. Comparison between 2011–2015 (**left**) and 2015–2019 (**right**). Source: Padrón Continuo (Continuous Population Register), INE. Note: Sphere size represents metropolitan growth in absolute figures, reaching a maximum of 238,000 people (Madrid), during the second period analyzed. Blue spheres show that the whole FUA grew, whereas white ones indicate population decline.

Although there were multiple circumstances, the deurbanization stage was the most common in the Spanish FUAs during the economic crisis phase. By contrast, in the post-crisis period, suburbanization (with relative decentralization, as rings acquired more inhabitants than cores) was the predominant urban stae. As a whole (taking cores and peripheries together), the 69 FUAs had an annual growth of 0.44% between 2015 and 2019, as cores increased by 0.32% and peripheries grew by slightly more (0.59%). In the vast majority of cases (40 out of the 69 FUAs analyzed), population growth became positive in this period, and in 32 of them, both city cores and their peripheries grew. At the other end of the spectrum, 29 FUAs lost population, and in 15 of them, both urban core and ring populations decreased simultaneously. By contrast, 14 city cores lost inhabitants, whereas their peripheral municipalities did not. Finally, the opposite phenomenon occurred in the eight remaining cases. Therefore, the general picture is especially diverse, resulting in multiple timing and (positive and negative) population growth combinations in urban cores and peripheries. Algeciras, Almería, Girona, Lleida, Málaga, Marbella, Santiago de Compostela, Toledo, and Vitoria were the only nine FUAs in which the populations of both areas of the FUAs increased throughout the whole period analyzed. By contrast, in Ávila, Avilés, Cádiz, Córdoba, Cuenca, Ferrol, Gijón, Linares, Oviedo, and Ponferrada (10 FUAs), both city cores and suburban municipalities lost population throughout the entire timeframe under examination.

Figure 2 presents the same data shown in Figure 1 from a new perspective, with graphs now focusing on differences between cores and peripheries. The data show that, in 24 out of the 51 urban cores that lost population during the economic crisis phase, growth was positive in the second period. This means that most of them, namely, 27 cities, all situated in FUAs where growth was negative (white spheres), continued to lose population. In the opposite quadrant, blue spheres show where FUA growth was positive: Nearly all urban cores that gained population during the economic crisis phase (16 out of 18) continued to grow in the post-crisis period. Cartagena and Jerez, the only two exceptions, reversed their previous trend. As for peripheries, those that grew in the economic crisis phase continued to do so during the post-crisis period and, in fact, experienced much greater increases than urban cores. Those that decreased in the first period continued to do so, though at a slower pace than cores.

**Figure 2.** Cumulative annual growth rates (CAGRs) for the 69 Spanish FUAs in 2011–2015 and 2015–2019. Comparison between urban cores (**left**) and peripheral municipalities (**right**). Source: Padrón Continuo (Continuous Population Register), INE. Note: Sphere size represents metropolitan growth in absolute figures, reaching a maximum of 238,000 people (Madrid), during the second period analyzed. Blue spheres show that the whole FUA grew, whereas white ones indicate population decline.
