It’s not the last word or anything, but I found this survey of entry level classes of City of London banks to be interesting (I’m in the UK for the semester). Less than half Brits, and 14% Italian, more than any European country/ethnicity/whatever, including Germany and France if you like your countries big, Spain if you like your countries poor, and Ireland if you like your countries English speaking. This anonymous banker thinks it is because Italians are desperate and charming. Your mileage may vary!