Imagine: 1) I'm the owner of a single family home 2) My income drops to roughly zero because of AI 3) My property values go through the roof 4) I now owe 2.5% of these sky-rocketing property values every year, to be paid from my non-existent income Doesn't this scenario lead to me either selling my "gifted" shares to pay property taxes, or ending up a renter at best and homeless at worst? I can imagine this proposal…
Just as a UBI gives people an income floor, I think that a land tax should come with a personal allowance below which you are exempt.
To do some rough calculations, the US state with the highest population density is New Jersey, at 1,210.1 people per square mile, which equates to 23,038 square feet per person. The average American house size is apparently 2,687 square feet, which is typically shared by multiple people, so the allowance could be comfortably set to maybe 10,000 square feet per person.