They won‘t leave. They never do. Maybe a hand full of them but they contributed nothing to society anyway but en large the rich never leave in droves over taxes. Their businesses are in this country and they simply can‘t just move it someplace else without huge upfront costs. Even the centrists know this. They‘re just afraid to not be welcomed at lavish events anymore I guess. And some of them are straight up bought I assume. But yeah, tax the rich god damnit. They‘re all bark and no bite.

They cannot take their factories, mines, shops, etc with them. They may take their money, but their money is usually tied to their business. If their business is nationalized, because they left it behind, their wealth suddenly is backed by nothing.

for one, i don't think that they actually mean "wealthy individuals" but "big companies", like adidas producing shoes or sth. basically there is absolutely not a single reason why such a big company would be located in country X and not country Y besides economic incentives. realistically, they could produce equally well everywhere in the world, they're just gonna go wherever labor costs and taxes are lowest. these jobs would be lost if the company leaves.

then again, these companies probably already moved to china 30 years ago. and who's left probably has a hard time leaving.

also it should be noted that this kind of analysis lacks vision. sure, jobs would be lost. so what, we're gonna have mass unemployment one way or another. better to accept that and deal with that, instead of clinging to an old economic system that is doomed to fail anyways.

anyways to solve problems, one needs to patiently think about them. since being patient is not spectacular, few are inclined towards it, and even fewer succeed. so we're not gonna get good answers to any of the world's problems until somebody who (1) cares and (2) has a good understanding of the world bothers to actually make up meaningful solutions, i figure.

They bring very little in compared to their wealth, and comparatively very little tax wise, but lets not pretend like they bring little to the economy itself.

They do spend money where they are. They dine in fine restaurants, they hire private chefs, they have staff for their houses, they buy fancy cars etc. They probably employ thousands of people in various personal support roles (I'm not talking jobs like they run a business and have 10,000 employees, but the cleaning people, the personal assistants, the chauffeurs etc. Things they would have wherever they are even without a business.)

There are entire industries that even cater to them, like if they purchase a mega yacht and france has that industry.

The do something for the local economy, they just pay little taxes besides any local consumption taxes, but taxes is not the entire economy.

Edits to better express what i was trying to say.

If there were greater places for them to live in, they would be living there rather than were they are living now.

If low taxation was all that mattered, all the rich people would be living in the small-state paradise which is Ethiopia Somalia.

That threat has always been bullshit.

We can just hang them and take their money.

Calling Macron and Le Pen, respectively, "center" and "right", is a very .world moment indeed

The pension system thing is complicated but there is a simple answer to your second question: the ultra wealthy pay very little tax, all across the West, because they have no personal income and instead hold stakes in legal entities that buy everything they want.

Zucman has written a bunch of articles on the subject, including one on the US