People have been saying it about NYC forever, but last I checked the millionaire+ population of NYC had grown, not shrunk.

Of course the number of millionaires has grown on an absolute basis given inflation and the strong stock market.

To control for this look at NYC's share of the nation's millionaires, which shrank from 6.5% in 2010 to 4.2% in 2022.

https://cbcny.org/research/hidden-cost-new-yorks-shrinking-m...

Okay, so aggressive taxation should then have its (proven) benefits weighed against the (dubious) benefits of having 30% of your millionaires change their legal residence to be elsewhere.

I think taxes still handily win with room to spare. Even more: plenty of those rich people are still in NY and participating in its economy (legal residence != where you actually physically live, especially if you have resources to game residence by owning multiple properties).

Perhaps I missed it, but your TL;DR seems like a personal view rather than what is in the article. Do you have sources for your claims?

Not OP, but one example I can think of: Jeff Bezos moved from Washington state to Florida two years after Washington enacted a 7% capital gains tax "on the sale or exchange of long-term capital assets such as stocks, bonds, business interests, or other investments and tangible assets"[1] which "reportedly helped him save $1 billion in taxes."[2]

[1]: https://dor.wa.gov/taxes-rates/other-taxes/capital-gains-tax

[2]: https://finance.yahoo.com/news/jeff-bezos-moved-florida-impa...

It’s not really hard to see such a migration if you simply follow the money. See [0] and [1]

[0] https://www.forthcapital.com/uk/articles/2025-wealth-migrati...

[1] https://www.henleyglobal.com/publications/henley-private-wea...

There's plenty of studies on this. There's unsurprisingly a modest but statistically significant migration of millionaires from high-tax to low-tax jurisdictions.

https://www.asanet.org/wp-content/uploads/attach/journals/ju...

Ah yes. There are famously no billionaires who live in New York City

I mean, net millionares are massively up in the UK, not nearly as many left as are created, so it's not really a good case study there.

I assume you have a credible source for that (baseless) claim and for what year exactly?

Well, the usual millionaires fleeing data for the Uk is the Henley & Partners report[0] (a wealth management firm, which is not a reputable source for these statistics, they simply want to attract clients, so its advertising). That reports 16,500 millionaires leaving the UK in 2025.

This report has been critisiced, with the data likely compeltely or partially fabricated [1]. [2] provides a graph for millionaires by year (note covid data unreliable) and you can see the number remains steady, so therefore if there was net migration it must be made up for by new millionaires anyway. In fact [3] (with UBS data) suggests the number of millionaires went up by 20% between 2017 and 2025 in the uk, despite 2% migration.

[0]: https://www.ftadviser.com/content/e80ff28f-97fb-4e85-811f-c0...

[1]: https://taxpolicy.org.uk/2025/07/27/henley-partners-milliona...

[2]: https://taxjustice.net/press/millionaire-exodus-did-not-occu...

[3]: https://taxjustice.net/press/millionaire-exodus-claim-backtr...

And it is just inflation. Does a million quid even last a lifetime now?