I'm trying to think through the effects of a Georgian tax system, where the levy is based on "the value of the land". But in my conception, that's either very small, or it actually includes improvement value (and improvements on neighboring land). The entire value of land is how it's used, I think.
Relatedly, land (and capital generally) is a stock, and taxes are generally a flow. The proposal seems not to be a one-time tax to just take the land value from current owners and then let future owners enjoy the (unfair) gains, so it's something like "imputed rent" or "this year's expected proceeds from using just the land with no labor or improvements". I'm unsure how the former isn't including improvements and usage, nor how the latter isn't close to zero.
Are there any examples of how much to tax a few properties in a real (or real-ish) example? Feel free to specify two small apartment buildings with given (but varying over time) end-user rents, vacancy rates, age of building, etc. What part of their actual net profit is due to land value? Likewise for a homeowner with 1/10 acre and an assessed value of $500k (split evenly for tax and insurance purposes between land and house, but actual replacement cost for the house closer to $400k, and Zillow says the value should be closer to $650k).
Here's one example: my house! Our purchase price was around $460k. You can estimate the value of unimproved land by subtracting the value the house is insured for from the actual price. It's insured for $360k, so our land value would be estimated at $100k. (I'm sure there are better ways to estimate this-- and I imagine if taxes depended on it, people might try to change their insurance amounts to game the system-- but it works for now.)
From a quick look at Craigslist, it seems we could rent the place out for maybe $2,500 per month. Multiply that by $100k/$460k and you get that around $540 of the rent is coming from land value, which comes out to a yearly property tax of $6500 or about 6.5% of land value.
Landlords sometimes use a rule of thumb that a property is a good investment if you can charge at least 6% of the purchase price in rent per year. This is pretty similar to the 6.5% I got. In general, it seems that a roughly 5-6.5% tax on the unimproved land value gets you around 100% of the land rents.
($6500 is about 3x our current property taxes, which I think correctly reflects the fact that our house is in a pretty desirable location and the house itself isn't that amazing. Actually, the current Redfin estimate on our house is at $540k, so it would be even higher than that.)