Resumen:
The number of immigrants in a given country can be estimated through a variety of methods, and a comparison of the estimates obtained can shed light on their respective merits and limitations.
Since 1996, Spain has set up a population register that aggregates the data from all the municipal registers. As it includes all immigrants residing in the country, their number can be determined directly. In addition, the 2007 National Immigrant Survey allows the estimation of immigrants’ fertility rates. Starting out from these
immigrant fertility rates by sex and age, Luis ROSERO-BIXBY, Teresa CASTRO-MARTÍN, David REHER and María SÁNCHEZ-DOMÍNGUEZ deduce the number of immigrants in Spain by country of origin from the number of births to immigrants recorded in the Spanish birth registry. By comparing their results with the count of immigrants given in the population register, they put their method to the test
and point up the inaccuracies of the register, notably the probable over-counting of immigrant men.