Image copyright Thinkstock Image caption The ultra-rich are more likely to be graduates, not self-taught self-starters

Are the super-rich more likely to be better educated? Or have they spurned scholarship and dedicated themselves to the serious business of being seriously rich?

According to a global census of dollar billionaires, almost two-thirds have a university degree. That means that even for countries with a high level of graduates, billionaires are disproportionately likely to have gone to university.

In the UK, more than four out of five billionaires were in higher education - not so much rags to riches as rag week to riches.

The educational insights are from an annual profile of the uber-rich, the Wealth-X and UBS Billionaire Census, produced by the Swiss banking group and a Singapore-based financial intelligence firm.

It examines the wealth and background of more than 2,300 billionaires - and the findings undermine the image of the wealthy as being self-taught self-starters trained on the market stall.

As well as being much more likely to be graduates, a quarter have postgraduate degrees and more than one in 10 has a doctorate.

This map of wealth also shows that these dollar billionaires - worth at least £620m and typically more than three times this amount - are likely to have attended some of the traditionally most prestigious universities.

The top 20 for universities producing billionaires is dominated by blue-chip, elite US institutions, which take 16 of the places.

Elite institutions

The University of Pennsylvania has produced more than any other institution, followed by Harvard, Yale, the University of Southern California, Princeton, Cornell and Stanford.

And the most likely way of making money is by dealing in money, with billionaires mostly making their fortunes through finance, banking and investment.

Image copyright Thinkstock Image caption University of Pennsylvania has produced the most billionaires

But there are also some indications that the geography of the super rich is changing. Reflecting India's growing economy, the University of Mumbai is in ninth place in the league table.

The only UK university in this wealth list is the London School of Economics, in 10th place, with no place for Oxford or Cambridge.

The rise of Russia's wealthy is reflected in the 11th place for Lomonosov Moscow State University.

But the dominance of the US universities is not simply about the US producing more billionaires. More than a quarter of the billionaires who attended US universities to take undergraduate degrees were from other countries.

This was even more the case for postgraduate courses in the US, where 39% came from overseas.

There could also be something of a time-lag, because the average age of this group is 63, attending the university systems of four decades ago.

University donations

The connection with university carries into later life. More than half of billionaires are involved in philanthropic projects and the biggest single cause they support is education - and within this category, it is particularly higher education that gets their backing.

It helps to explain how Harvard's fundraising drive could set an eye-watering target of $6.5bn (£4bn).

Image copyright PA Image caption Billionaires are increasingly concentrated in a few global cities, such as London, Moscow and New York

The study shows a pattern of wealth being concentrated in a small number of places. More than 40% of billionaires in Europe live in just 10 cities, headed by Moscow and London. Globally the biggest city for billionaires is New York.

It also creates some jarring contrasts. Nigeria has become the country with the most number of children without access to any education - while this report shows that Nigeria is on course to have the most billionaires in Africa.

There have been repeated international studies from organisations such as the Organisation for Economic Co-operation and Development showing that going to university remains a strong investment in terms of improving the chance of a higher-income job.

Such studies have rejected the idea that not going to university could be a smarter move or that the value of a degree will fall below the cost of tuition.

But Frank Furedi, author, social commentator and former professor of sociology, says that one of the "big secrets" of the expansion of higher education has been a growing gap between the most prestigious universities and the rest.

"The hierarchy has become more fixed," says Prof Furedi.

These top universities have become the place where "global players gather".

He says there has always been a tension between universities promoting social mobility and being the route for handing on advantage to the next generation.

"Education has always been contradictory, it's the way that some people make their way up and it's the way of consolidating privilege."