In "Progress and Poverty," in advance of the statement of his proposition, Henry George writes: "Nor to take rent for public use is it necessary that the State should bother with the letting of lands, and assume chances of favoritism, collusion, and corruption this might involve. It is not necessary that any new machinery should be created. ...We already take some rent by taxation. We have only to make some changes in the modes of taxation to take it all."
In shifting emphasis from taxation to rent, the argument was advanced that taxation of land values was self-defeating in that the market price of land would fall with increase of tax rate, ultimately eliminating the base upon which the tax would be levied. A more careful study of this phenomenon, however, should prove the fallacy of the argument. The conclusions should be reached that: "As the tax rate is increased and approaches infinity as a limit, land value (price) decreases and approaches zero as a limit, and tax revenue increases, approaching the full economic rent as a limit." From this, no matter how high the tax rate, there would always be some base upon which to levy, and tax revenue would increase with increase in tax rates. At no rate could tax revenue exceed the full economic rent.
To demonstrate the above statements we may set up an algebraic equation based upon the Law of Rent. Rent is a monopoly price, "all that the traffic will bear." It is a fixed amount at any given instance and is comprised of taxes, interest, and any other charges that may be against the land. The market price of land, popularly known as, and herein referred to as Land Value, is the capitalization of that part of rent assured to the owner. "
On these premises,
let R = annual rent of land
let a = current rate of taxation, %
let b = prevailing rate of interest, %
let L = Land Value (price)
then R = (a + b) L
let c = increase in rate of taxation, % points
and X = resultant Land Value (price)
then R = (a + b + c) X
from which X = (a + b)L / a + b + c
(source: The Significance of Land Value Taxation and Land Speculation by Julian Hickok
http://www.cooperativeindividualism.org/hickok-julian_significance-of-land-value-taxation-and-land-speculation-1969.html )