This article has some evidence that is reassuring in a way for pupils and students who are motivated and want to do well… the vast majority of billionaires went to university and are highly educated.
Sometimes pupils are misled a bit by the success stories of Richard Branson and others who left school with no qualifications… but no everyone is lucky enough like Branson to have a millionaire relative who financed his early failures.
http://www.bbc.co.uk/news/business-29786836