So it turns out that "But corporations would just move somewhere else" wasn't a valid argument against raising corporation tax all along, and countries could ha

So it turns out that "But corporations would just move somewhere else" wasn't a valid argument against raising corporation tax all along, and countries could have agreed this 100 years ago. Now let's create a wealth tax using the same international approach. The treaty could say that each country should have a wealth tax of say 8%, with the first $100m being tax free. For comparison, the average US household has a net worth of $120k and pays $10k in taxes every year. If a billionaire lives in a country that doesn't join the treaty, then the countries which have joined can refuse to allow that billionaire to travel to or through their territory, or own any assets in their jurisdiction.