(Planet Money NPR) - In late January, Senator Elizabeth Warren, who's in the race to become president in 2020, added a new kind of tax to the American conversation, causing anxious pacing on superyachts in every port: a wealth tax. It's a cousin of the property tax, but it encompasses all forms of wealth: cash, stocks, jewelry, thoroughbred horses, jets, everything. Warren calls the policy her "Ultra-Millionaire Tax." Read More