I'm in Singapore and that's missing a lot of context. The supply of government housing is not nearly enough to meet supply and there are restrictions on who can apply and even then it's a lottery. Property is still considered an investment, and no wonder when resale prices for the HDB flats are significantly higher than the purchase price.

IMO the HDB flats should not be saleable on the open market and can only be sold back to the government (subject to inflation and depreciation adjustments that no-one's going to agree to) but I'm an expat and not eligible to partake in the upside so I might be a bit biased.

All that being said they have done a better job than most of making government housing both accessible and appealing even if it means that I'm having to find a new place to live in the middle of an inflationary period (even as the country is seeing net emigration for the first time in decades, wth is going on??)

> Could that really work at a local level where people can freely move cities? Local UBI seems hard to implement in a non city state.

Only if you overthink it. An "open border" LVT+UBI system is self-balancing; a flood of immigrants would drive up demand for land, which drives up its value, which raises LVT revenue, which raises total UBI disbursement, which keeps each individual's UBI stable.

That said, it would work even better at a state level, and better still at a national/federal level.

> why not take the Singaporean approach?

The Singaporean approach (IIUC) includes land leases, which is in practice equivalent to a 100% LVT (assuming the government prices the lease at the land's full value).