It was famously revealed during their divorce last year that Angelina Jolie and Brad Pitt owned no fewer than 12 multi-million-dollar homes across the world.
Now new research reveals that Jolie and Pitt are part of a growing "global citizen class" of multi-millionaires who spend their lives jetting between multiple properties in the planet's most desirable locations.
The report, by the research firm Wealth-X, found that as private jet travel has become more accessible and faster internet speeds have made working from the beach or ski lodge more practical, the world's wealthiest people are buying up multiple homes.
More than 10 per cent of the world's 212,625 ultra-high net worth individuals - defined as those with assets of at least NZ$40 million - own five or more properties in addition to their main home, the research found.
"More than ever before these homes of the wealthy will be spread far and wide, across different countries and continents," said the report, produced in partnership with the luxury estate agents Warburg Realty and Barnes International Realty.
Clelia Warburg Peters, the president of Warburg Realty and great-great-granddaughter of the financier Felix Warburg, said: "An emerging trend is the growth of the global citizen class, many of whom are extremely wealthy individuals who think of themselves as citizens of the world, as much as citizens of their home country."
She said they had a "huge degree of mobility" in their assets, but noted that there was a growing "political pushback against this class".
The report said the growth in wealthy's people's multi-home portfolios had been driven by the increased ease of high-end travel.
The most popular cities for second homes are Hong Kong, for its proximity to China; London, which has recently seen increased interest because of the fall in the value of the pound; Los Angeles, for celebrities and their admirers; New York; and Singapore, which has shot up the list as a result of its proximity to fast-growing countries in Southeast Asia.
Wealth-X said the number of wealthy people with more than five homes could easily be far higher than 21,000, because its research was compiled from publicly available data and would not count homes bought through trusts, offshore companies or owned in the name of a spouse or other relative.
Oxfam, which last week said the world's eight richest people control the same wealth between them as the poorest half of the globe's population, said the growing property portfolios were another sign of a global inequality crisis.
"An elite group are able to channel their wealth into multiple properties while millions of people don't have a roof over their heads," said Oxfam's inequality policy adviser, Chiara Mariotti. "We need to rebalance our economies so they work in the interests of everyone - especially the poorest - for example by ensuring the super-rich pay their fair share towards the fight against poverty."
London was named the most desirable city for the wealthy to buy property because of its personal and business safety, culture, education and shopping, and despite the government increasing stamp duty on second homes worth more than £1.5m to £15m last year. The report said a luxury residence in London was "widely regarded as a lifestyle necessity for the wealthy elite".
More than 6400 ultra-high net worth individuals live in London, the second-highest population after New York with 8375. London's super-wealthy, who are worth an average of US$130m, are more diverse than New York's, with 37 per cent being foreigners compared with 26 per cent in New York.
"London is truly an international playground for the world's ultra-wealthy," Warburg Peters said.
The fall in the value of the pound triggered by the Brexit vote and a recent boom in new luxury developments along the Thames are said to have created a "once-in-a-generation buying opportunity" in London.
Winston Chesterfield, a director of Wealth-X who helped compile the report, said a place on the beach and a ski lodge were the most popular property purchases "and taken with a country house and town house, it doesn't take long to get to five".