@FeloniousPunk @peterbrown @GrantMeStrength The US has lots of test cases, due to differences between state income tax rates (excess of 10% in some states, zero on others), and millionaires always say the next little bit would be the one to make them move. But they're giving up money to stay where they are already, and the difference in amounts is minor. So if money would make them leave, they'd have already left.