You may not realise it but Spain use to benefit from very steady and continuous growth. This started around 1980. Since then they have gone from strength to strength. One of their biggest banks Santander even bought out Abbey a large UK high street bank.
Spain at the moment is the 9th largest economy on the globe. Their wealth came about because they modernised their infrastructure and deregulated the economy from the old way of Franco.
A big earner for Spain was always their tourist industry. Many Brits have purchased houses in Spain on Golf resorts and other ex pat housing estates. All of this meant gave huge growth to the Spanish economy.
Unfortunately the recession which started in 2008 has hit Spain very hard. Many people are now out of work and unemployment levels are rising. Spanish job sites such as Trabajo Barcelona have seen large rises in traffic figures over the past year.
One of the job sectors hit hardest was the construction industry. This was a booming sector which employed many people including many immigrants.
Spain has seen a large increased in immigrants from both Spanish speaking South American countries as well as Eastern European countries due to their thriving economy.