we need to tax (update: sorry, not wealth) income.

90% tax on all income over $100 million. That would mean anyone making $500 million would still be bringing in $40 million a year. If you need more than $40 million a year you are just greedy and want to be some kind of king.

This would also mean the power of wealth would be neutralized.

This would have barely any actual effect since the number of people with such high income is nearly zero.

All it means is they would spend more on tax avoidance schemes which is wasteful.

I guess you think this high marginal tax rate would hold for unrealized capital gains? Otherwise your conclusion don't really hold.

Personally I prefer a wealth tax.

> 90% tax on all income over $100 million.

That's an income tax, not a wealth tax?