> Expats often chose their location based on such factors.

You're not answering the question I wrote. Recreational or investment properties in foreign countries, i.e. not a peron's only property in their home country.

Expats pick a country to live and work in. They don't get to pick different countries for income tax, for property tax, for company tax, etc., like a billionaire being a US citizen with a swiss bank account, luxemburg company, luxury vacation homes in e.g., gated communities in Morocco.

(Also note that this isn't a discussion of just property tax, but billionaires avoiding tax in general.)

> Good luck finding someone who actually pays zero property tax on US land they own

Observe the point above - US citizens owning land in foreign countries.

Also, US citizens paying way less by severely misreporting and paying people to look the other way, like the earlier example.

> Comparing wealthy taxation is only meaningful based on percentages.

All taxes should be fixed, unavoidable percentages yes, that is my original argument. Progressive tax doesn't fix things because it doesn't hit the ultra wealthy like people think, as those evade the flippin' thing anyway. Deal with the corruption and evasion, get some proper (and fixed) rates to apply to their business, and you won't need complex progressive tax systems.