The National Statistics Institute has just published the latest data from the Padron Municipal (valid as of 1 January 2008). 5,220,577 foreign born residents in Spain at that point. This was an increase of 701,023 over 1 January 2007. The evolution of the foreign born population can be seen in the chart below.
To give us some idea where we are here, Spain's population increased by 862,774 people during 2007. Natural increase in the Spanish population accounted for 161,751and the rest of the increase was a result of net inward migration.
Residents by country
Basically I would argue that the whole future evolution of the Spanish economy depends on what now happens to all these immigrants (who have basically compensated for the "missing births" in Spain which have been produced by the presence of lowest-low fertility for such a long time.
Here is a chart showing the principal migrant source countries outside of Western Europe. In Western Europe the UK is far and away the largest origin point, with 352,000 residents at the end of 2007. It is also interesting to note how the increase in the numbers of new residents from Western Europe has now slowed considerably. Now that the housing boom has fully burst it is unlikely the inflows from these sources will pick up very much in the near future.
Outside Western Europe the big news this year is that Romania has jumped into the number one slot, with 728,961 residents, overtaking the previous number one, Morocco (who now have 644,688 residents). The number of Ecuadorians actually dropped by 6,989 in 2007 and now stands at 427,099. It is hard to say anything conclusive about this, but at face value it does seem to suggest that the idea that East Europeans would be transient migrants and Latin Americans more permanent may be a large over-simplification. The Romanian community in Spain (as well as in Italy I suspect) seems now to be well established, and it may well be that many of these migrants have now decided to change their country permanently, we will see. If that is the case the implications of this (with 700,000 people largely of working age in Spain and a similar number in Italy) are enormous for the future of a country with a working population of only just over 10 million, and a population which due to its own low fertility would soon be contracting naturally. Unfortunately few people are thinking about this problem at this point.