The average cost of a home in Mayfair is still more expensive than Manhattan, despite a slowdown across the prime central London property market.
Homes in the exclusive West End neighbourhood are valued at £3,850sq ft, according to a new report by luxury residential specialists Beauchamp Estates, which compares more than 500 ultra-prime property listings across the globe.
The average listing price in Mayfair currently stands at £18.4 million. While homes in New York's well-heeled Manhattan district have higher price tags, they are generally substantially bigger, so the average cost of buying is higher, at £21.5 million (£3,575sq ft).
The price-per-square-foot measure is an important way of comparing values, traditionally used by surveyors and land valuers, that can turn assumptions on their head.
The Brexit effect: Sterling vs. Dollars
Ultra High Net Worth Individuals (UHNWIs), the global group of 300,000 people whose fortunes worth at least £40 million, regularly buy and sell multi-million pound properties all over the world.
Exclusivity is their ultimate wish and they often demand that they are the first - or even the only - person to view a house that's been listed before they will consider it for purchase.
Credit Suisse reports that there are now 4,700 UNHWIs in the UK, after 700 saw the value of their personal wealth fall in 2016, mainly as a result of the fall in sterling after the vote to leave the EU.
While the pound's plunge is bad news for British buyers, it provides new opportunities for global UHNWIs who operate in dollars.
A US dollar buyer purchasing a typical 3,900sq ft ultra-prime apartment in Mayfair now pays $18.5 million, compared to $20.7 million in 2015 - saving $2.2 million, explains Jed Garfield, managing partner at New York-based luxury residential property agents Leslie J Garfield.
The hope is that foreign buyers will boost the UK's stagnant prime property market this year.
However, James Moran, from Winkworth estate agents, believes this hasn't yet happened despite being widely expected.
He says: "Rather than an influx of foreign buyers coming in vast numbers, the ones who were already interested in buying have increased spending power and are looking to invest more."
The Trump Factor: New York
Sales of luxury homes in Manhattan were also hit last year, with the average property selling for $6.8 million in 2016, down from $8.6 million the previous year.
A report by Leslie J Garfield says: "Due to the currency play and also uncertainty caused by the "Trump Factor", over the last six months the number of enquiries and sales in Manhattan has declined considerably."
However, the report predicts the market will bounce back this year thanks to President Trump's promise of tax reductions for the wealthy, with the continual rise of the stock market since the election is a strong indicator that the property market will follow suit.