That is part of the solution, but you're dreaming if you think you can tax people at 90% and expect them to continue to produce. I've packed up and relocated for less. I've also turned down work that I otherwise would have accepted, just because I know the government will take half. There would have been no Steve Jobs (at least not in the US) at 90% marginal tax rates.
And we need better international coordination. In this future scenario the super rich that take their marbles and go home will be banned from travelling into the countries that co-operate. The super rich act like they gain nothing of value from our social safety nets, but they do. Happy liberal cities cost money. I don't want a world where the Koch Brothers can leisurely enjoy a city like Toronto, Paris, or Tokyo without contributing a dime to the others around them that made them rich.
