According to a 1996 IMF estimate, money laundered annually amounts to 2-5% of world GDP (between 800 billion and 2 trillion US dollars in today's terms). The lower figure is considerably larger than an average European economy, such as Spain's.
It is important to realize that money laundering takes place within the banking system. Big amounts of cash are spread among numerous accounts (sometimes in free economic zones, financial off shore centers, and tax havens), converted to bearer financial instruments (money orders, bonds), or placed with trusts and charities. The money is then transferred to other locations, sometimes as bogus payments for "goods and services" against fake or inflated invoices issued by holding companies owned by lawyers or accountants on behalf of unnamed beneficiaries. The transferred funds are re-assembled in their destination and often "shipped" back to the point of origin under a new identity. The laundered funds are then invested in the legitimate economy. It is a simple procedure - yet an effective one. It results in either no paper trail - or too much of it. The accounts are invariably liquidated and all traces erased.