New York City has been unveiled as home to the most billionaires, which has helped the city's luxury housing prices rise, according to Barron's. There are 85 billionaires who make New York City their main residence, including former mayor Michael Bloomberg and David Koch. Their presence in the city has helped push luxury property prices up 15% over the last five years to $3,220 per square foot. But New York is actually still considered a discount compared to Hong Kong and Tokyo, where luxury homes cost nearly twice as much. In US dollars, it cost $8,370 per square foot for luxury property in Hong Kong, which is home to 79 billionaires and the most expensive real estate in the world. Luxury housing prices have soared 51% over the last five years in Hong Kong. Sophie Chick, head of Savills World Research said: “It is no coincidence that many of the cities with the largest number of billionaires are also among the most expensive cities in the world for ultra-prime residential property.” Beijing is an exception because luxury prices haven’t yet caught up with the pace of billionaires. Beijing has 61 billionaires, but the city remains one of the less expensive places to buy a luxury home at about $1,780 per square foot. This is still double what it was five years ago. Shanghai, which hosts 45 billionaires, has an average price of $2740 per square foot. A Savills World Research report said: “China’s relatively recent growth in wealth is also reflected in the average age of its billionaires—56 years. This compares with 66 for the U.S. and 64 globally.” The cheapest home to billionaires was revealed to be Dubai, where despite luxury home prices increasing 13% over the past year, they are still at $750 per square foot. Dubai is home to 15 billionaires.