Yeah, it should probably be a progressive rate but with the catch being that the rate never stops increasing!

So maybe we start very small -- a 1% tax on wealth over $10 million. And that $10 million is also our magic number below which the wealth tax cannot drag you, which will be important in a second.

Then there are a few tiers above that which don't need to be fancy. Maybe add 1% to the incremental rate per $100 million.

But then at $1 billion, the incremental rate becomes 100%. So if you end up over the limit you essentially get set back to $1 billion, which is further taxed according to our imaginary progressive rate.

I also wonder if it might be a good idea to provide a strong incentive for the individual to disburse their gains to charitable causes rather than the burden of administration always falling to the government. One interesting thing might be to introduce one or two even higher brackets that go above 100%.

Say that at $2 billion the tax on each additional dollar becomes 150%. That means that if you get lazy or just want to hoard wealth short term, you not only get knocked back down to $1 billion but lower than that.

Honestly though, we don't need that complexity. 100% wealth tax on anything over a billion and the government does extravagant shit to honor the top payers each year and names buildings after them and whatnot.