The richest 1% of Americans now hold 25% of the country's wealth and more needs to be done to boost equality, Nobel Prize winning US economist Joseph Stiglitz has said.

Mr Stiglitz, speaking in Davos, said this was a result of the top 1% seeing their wealth double since 1980.

By contrast, he said that the median income level in the US had not changed since the early 1990s.

But Mr Stiglitz had praise for Brazil and the Scandinavian countries.

Speaking to the BBC's economics editor Stephanie Flanders at the World Economic Forum in Davos, Switzerland, Mr Stiglitz called for more work to boost the educational opportunities of the "bottom 50%" of Americans, higher minimum wages, and more collective bargaining in the workplace.

"America likes to think of itself as a land of equality and opportunity, the so-called American dream is very deep to our sense of identity," he said.

"The stats show otherwise, the US has one of the worst opportunity rates of any of the advanced economies. A child's life chances are more dependent on the income of his or her parents than most other industrial economies."

Mr Stiglitz contrasted the situation in the US in the past 30 years with that from the Second World War to 1980, when he said the US economy enjoyed "rapid growth in which we all grew together".

Looking outside the US, Mr Stiglitz praised Brazil, where he said a major bipartisan effort over the past 20 years had markedly improved equality in the country.

Meanwhile, he said that the Scandinavian countries were leading the way with the highest levels of equality.