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.)
To clarify, the tax Georgists want (Land Value Tax or LVT) is a tax on the Economic Rent of the land. While you can find more detailed explanations e.g. here (excellent overview by Lars Doucet, the whole series is recommended), the tax seems to (to my understanding) wind up being around 3-4% of the value of the land per year, after all the math.
As a very basic example, the economic rent of a piece of land (not buildings, just land) from the above:
If a piece of land costs $10,000 to buy, and is leased for $500/year, then an LVT that captures 100% of the land rent is $500/year, which works out to a 5% annual tax of the land value.
While pure Georgism advocates for taxing 100% of that $500/year economic rent, most of the actual proposals top out at 85%, and the more realistic ones are less than that.
Also keep in mind a) that this is tax on the land value, not including the value of the house/apartment building/office/etc. on top of it, and b) this replaces existing property taxes, which already exist everywhere and tax both the land and whatever's on top of it.
My understanding of Georgist policy is that the point is that land shouldn't be a stock at all. It should not be an appreciating asset that an individual/firm holds.
This is for a number of reasons, including but not limited to:
Instead, land should be put to productive use, so the owner can generate sufficient wealth to pay the LVT and have a little extra as a profit.
For all your Georgist needs, I recommend the substack Progress and Poverty.
For successful examples of Georgist policy, this article focuses on land policy in Singapore, while this one focuses on Norway.
Hope this helps!
There is a list of jurisdictions which implement LVT either via single tax on value, or a split tax where the value of improvements is assessed separately (and charged a lower rate):
https://en.wikipedia.org/wiki/Land_value_tax_in_the_United_States
I think the best candidate for you is probably the Pittsburgh Business District, which seems small and close to your example. Alternatively I suggest Altoona City, which has the most-like-the-Georgians-advocate scheme of high value tax and zero improvement tax.
All of these locations on the list should have public information available on the methods of assessment and actual revenue earned. Whether this can all be had over the internet is another matter, but following those threads should also bring up any studies done using their data.
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).