Are the Rich Really Leaving Britain?

Henley and Partners publish their private wealth migration report once a year. In their latest edition, the UK ranks dead last for the first time with a net outflow of 16,500 millionaires. This figure has been quoted in Parliament, picked up by newspapers, and used to frame debates about Britain's global competitiveness. It's a very worrying number, but it's also quite hard to verify.

Tim Harford looked into this claim on his BBC podcast, more or less. He interviewed the head of research at New World Wealth, who did the research underlying the migration report, who explained that their estimates rely on social media profiles, press coverage, and company filings. Hartford argued in his podcast quite rightly, that their sample was not representative and that you couldn't draw conclusions from it. Dan Needle of Tax Policy Associates went further.

In a forensic review published on his website, he pointed out that the report was riddled with statistical red flags. The firm had dropped all property wealth from its analysis between 2023 and 2025. Yet, its millionaire accounts barely moved, a result Needle described as impossible if the published methodology were real. New World Weld later told the FT that they hadn't actually changed their methodology, just their description of it.

Needle found digit patterns in the data with a suspiciously high frequency of even numbers and numbers where trailing digits cluster on zeros and fives with almost no ones. Statistically, he points out, the chance of that occurring naturally is about 1 in 240,000. more evidence. He says that the numbers were either manually created or manually adjusted.

Needle's analysis used wellestablished techniques to detect rigged numbers. I'll put a link to his more detailed analysis in the description, but he concluded that the figures were likely engineered rather than observed. Now, this doesn't mean that the rich are not leaving the UK. It just means that it's very difficult to know whether they are or not simply because good data doesn't exist.

To highlight the difficulty, the UK Office for Statistics Regulation recently suspended the official statistic status of the government's own wealth and asset survey collected by the Office for National Statistics following concerns raised by the ONS that the data is no longer of sufficient quality to meet users needs. The Financial Times, in a separate analysis, found that a wave of company directors have left Britain ...