Since the early 1990s, Spanish fertility has been among the lowest in the world, despite a small upturn observed in the last few years (1.35 children per woman in 2006). In this context, and despite a steady increase in life expectancy, population growth is set to level off and become negative in the coming decades. Yet at the same time, thanks to unprecedented economic prosperity, Spain's population has risen by 5 million over the last decade and now exceeds 45 million. This rapid growth, unique in Europe, is almost entirely attributable to immigration: the number of foreigners rose from 200,000 in 1981 to almost 4.5 million in early 2007. In this article, MARTA ROIG VILA and TERESA CASTRO MARTÍN examine the contribution of foreigners' fertility to population growth, both today and in the future. They approach the question by examining differences in fertility behaviour between Spanish women and foreign women, and between foreign women of different origins. After meticulous analysis of all available data, they interpret the observed differences with caution and conclude that a broader range of data is required before more detailed analyses can be attempted.
After nearly three decades of below-replacement fertility in Europe, there is general acceptance that low fertility is here to stay and that population ageing is an unavoidable prospect. But acceptance does not imply full resignation. In recent years, increasing attention has been paid to the role of immigrant populations, and on whether their youthful age pyramids and higher fertility would help lessen the anticipated consequences of Europe's subfertile, labour-short, ageing and declining populations (United Nations, 2001; Lutz and Scherbov, 2002; Teitelbaum, 2004). The debate has mainly focused on the rejuvenating effect of sustained entries of young adults, and less attention has been paid to the contribution of immigrant fertility, despite the fact that the proportion of children from foreign-born mothers is increasing significantly (Haug, Compton and Courbage, 2002).
In Spain, the immigration debate is relatively recent and has mainly focused on economic integration and social cohesion issues (Pérez Díaz et al., 2001; Colectivo IOÉ, 2002). However, Spain has had for several years one of the world's lowest fertility rates (less than 1.2 children per woman in the period 1995-1999) and has been singled by the United Nations as one of the countries with possibly the oldest age structure in the world in 2050 (United Nations, 2003). Therefore, the demographic impact of immigration is no longer absent from the debate. In particular, since the modest but sustained rise in fertility observed in recent years has coincided with an increase in immigration, this rise has been attributed to the presence of immigrant women (Instituto Nacional de Estadística, 2005). There are, however, important caveats concerning available evidence. How large is the fertility gap between foreign and Spanish women? Are conventional fertility rates appropriate to measure this gap? To what extent is the observed gap attributable to educational differentials? Are immigrants' childbearing patterns influenced by length of stay in the host country?
The existing literature has put forward different hypotheses to explain and predict the fertility patterns of immigrants (Kulu, 2005). Some authors suggest that the first generation of certain immigrant groups tend to maintain the reproductive norms and patterns of the country of origin (Abbasi-Shavazi and McDonald, 2002). A considerable number of studies support the adaptation hypothesis, which predicts that immigrants gradually adjust their reproductive behaviour to that of the host country (Andersson, 2004). Past research has also shown that convergence between the fertility patterns of migrants and those of the host country cannot be entirely attributed to behavioural change but also to the fact that migrants are a selected group of individuals, regarding education, marital status or parity, as well as other characteristics which are not as easily measured, such as work ethic and social mobility aspirations (Feliciano, 2005). …