> Perret says they didn't work for a lot of reasons. Among other things, it costs a lot to enforce. It pushed rich people out of the country, and the wealth taxes didn't raise a lot of revenue.

In France at least, it has been a topic of political debate for decades before the recent abolition and what's clear at this point is that it costed much less than what it brought (both in terms of law enforcement, and in terms of rich people moving out of the country).

> Unfortunately, nothing in her proposal justifies that. Why can't companies and people just move out of the US to avoid this?

A wealth tax isn't a tax on a company, it's a tax on the owner of the company so moving the company won't help here. And the owner leaving the US won't help either, since they will still have to pay taxes as long as they remain a US citizen. Renouncing to US citizenship would still be an option of course, but I'd expect the opportunity cost would be much higher than the cost of the tax itself.