One of the world's most celebrated economists has suggested the Turnbull Government introduce an inheritance tax to help address rising wealth inequality, which is making it increasingly difficult for middle-income Australians to buy their own homes.

Frenchman Thomas Piketty, who has been described as a "rock star economist" and packed out the Sydney Opera House for a lecture on Sunday, told Lateline that Australia was an outlier.

It struck him as odd the Australian Government imposed no taxes on those who had been bequeathed multi-million-dollar properties, while governments in the United States and Europe taxed the same gifts at between 40 and 45 per cent.

"Japan just raised its top inheritance tax rate from 45 to 55 per cent last year," Professor Piketty said.

"This was under a right-wing government by the way and I don't hear Angela Merkel or I didn't hear Cameron in Britain say he wanted to reduce the inheritance tax of 40 per cent to the Australian level of 0 per cent so this [Australia] is very unusual."

The author of the best-selling book Capital in the 21st Century said while small inheritances of 100,000 or 200,000 could remain tax free, it made perfect sense to levy tax on property transfers worth millions of dollars.

"The problem is not to raise tax for the pleasure of raising tax," Professor Piketty said.

"The objective must be to reduce taxes for others and in particular for those with middle wages and lower wages."

Professor Piketty's book showed the historical march of inequality around the globe and how those with accumulated wealth to invest had always made more money than those who relied entirely on their labour.

'Property tax system also not equitable'

Professor Piketty has warned of the dangers of allowing the uncorrected concentration of wealth in the hands of fewer and fewer people.

Between 1980 and 2010, the income share of the top 1 per cent of people in the world almost doubled.

Today, the three richest Australians have more wealth than the one million poorest.

Thomas Piketty's Capital in the 21st Century has sold around 2.5 million copies. ( Reuters: Charles Platiau )

Professor Piketty said it was much more difficult for the younger generation to access property than it was for their parents.

The share of national income in Australia going to the top 10 per cent is at the highest level it has been since 1951.

The top 10 per cent also happen to represent predominantly older Australians.

The property tax system in Australia is also not equitable, Professor Piketty argued..

"We see the same kinds of issues in a country like France, where you know you want to buy an apartment in Paris or in major cities," he observed.

"If you don't have a big family wealth, if you only have your labour income, this will have to be a very high labour income and that's a form of inequality through the transmission of property.

"Families who can transmit property and some part of the young generation who don't have that kind of family connection and wealth, this is a big challenge to the kind of meritocratic ideal that we believed in the postwar decades, where indeed it was easier to start from zero and access property yourself".