Some of them do mean it. They know that places with less wealth inequality are better places to live, even for the rich.

The problem is that even if they were willing to donate their entire wealth to the government, they’re only one of hundreds of billionaires, so their personal sacrifice isn’t going to change much. They’d just be one of the non-rich in a place with huge wealth inequality. So, before they do that, they want assurances that everyone else will do it too.

So, it comes down to whether politicians will do it. Many politicians won’t either because they’re rich themselves, or they’re “owned” by ultra-rich people who don’t want their hoards touched. But, even if the politicians were interested, it’s a tough issue because of offshore tax shelters and places like Monaco. When France tried to tax wealth, many of the wealthy just moved to Monaco, or to another place where their wealth was secure. And, as much as it sucks having the ultra-wealthy in the country not paying enough in taxes, it’s worse for them to take all their wealth and leave the country entirely.

The only thing that would really work is for the rich countries of the world to band together and agree on a minimum wealth tax, and then to deny entry to anybody who fled to a tax-shelter country. But, that would never happen both because it’s too ambitious and too many politicians are owned by the rich. And, because it’s a prisoner’s dilemma situation where there’s a huge incentive to be the country that defects from the deal and welcomes all the billionaires.