A nice idea I heard is to introduce a minimum tax rate based on wealth. Let’s say the magic number is 0.5%. Then you say, every individual (over some threshold etc) needs to pay max(normal tax calculation, 0.5% of wealth) .

What I like about it is that it doesn’t penalize people who already pay taxes. It’s a lower bound, not an extra.

What makes me weary about any such tax is that in practice, it seems to target the broad middle class - people who have enough assets to be interesting to the tax man, but who don’t have enough to hide it or avoid taxes.