Analysing increasing fertility differences within metropolitan areas. The cases of Barcelona and Madrid

Fernando Gil-Alonso, Universitat de Barcelona
Jordi Bayona-i-Carrasco, Universitat de Barcelona
Cristina López, Universitat de Barcelona
Miguel Rubiales, Universitat de Barcelona
Isabel Pujadas, Universitat de Barcelona

This paper intends to analyse the causes of these growing geographic fertility differences within urban areas using the two main Spanish metropolitan regions, Barcelona and Madrid, as case studies. Our main hypothesis is that growing geographical fertility differences are caused by metropolitan municipality spatial specialisation. This would be basically due to: 1) suburbanisation, 2) the impact of international immigration and 3) the fact that large metropolitan cores act as a “demographic filter” because the Second Demographic Transition has had a much stronger impact on them and, subsequently, have lower proportions of couples-with-children household compared to suburban municipalities. Birth and Death Statistics microdata published by the Spanish National Statistics Institute, and more specifically births by age and nationality of the mother and her municipality of residence, are used. Descriptive results show that, when results from the two main metropolitan areas are compared and confronted to our initial hypothesis, it can clearly be observed that each of the three main elements differentiating fertility behaviour do not have the same relevance in both metropolitan areas. In Madrid, suburbanisation would have recently become the main explanatory factor as Spanish women who live in those periphery municipalities which have most grown in the 21st century have the highest fertility levels. In Barcelona, however, foreigner settlement patterns, particularly those of Africans, would be the main explanatory element. Indeed, in the Catalan province, municipal TFR are strongly positively correlated with their African resident shares. This is not so for Madrid municipalities. Finally, regression analysis has confirmed that Spaniards' residential moves towards small and medium-size municipalities, together with foreigner settlement patterns, are the main elements currently explaining TFR differences within metropolitan areas. Fertility is much higher in municipalities that have received large numbers of Africans and Asians than in localities that have more Latin-Americans or Europeans.