Mostly two things: governments don't have the cash, and the payback math is too slow to bother. The mechanism behind the idea is real. In California, Proposition 13 caps how much assessed value can rise while one owner holds the property, and a sale triggers reassessment at the new purchase price. So the state already captures the higher tax revenue every time a long-held home changes hands, no incentive required. Warren Buffett has used one of his own properties as the classic illustration: bought decades ago for around $50,000 with property taxes near $1,500 a year, when at today's value the bill would run closer to $34,000. Now run the incentive against that. Say a city pays a homeowner roughly $20,000 to sell, and the reassessment nets the treasury about $4,000 more per year. The check takes five-plus years just to break even, funded by a government that may already be running a deficit. And even then, the money would miss the people it needs to move. What keeps most longtime owners in place is life stage, a low locked-in rate, and the cost and hassle of moving. A modest check touches none of those. Slow payoff, tight budgets, and a lever that misses its target: that's why you don't see the program.