RE: 'Til Debt Do You Part - Is Your Future Already Over?
I'm well aware of Georgism, and am not a fan. First off, while certainly well intentioned, any single solution answer is inherently unstable- Piketty's advocacy for progressive taxation is his main thrust, but is hardly as comprehensive as the Georgist solution. (See also Popper's distinction between holistic and piecemeal solutions and social planning.)
Next, and most importantly, Georgists (in my experience) seldom bring up the neegative environmental effects of their plan. In particular, the gross damage done to their topsoil by Australia. (Deforestation in Japan in this time period was severe, but mitigated by centuries old forest conservation policies instituted by the shogunate) Basing your entire system of tax revenue off the value of the land hardly incentivizes putting protections in place on the land that reduces the tax value of said land by preventing its exploitation. National parks and wildlife preserves owned by the government don't generate revenue at anywhere near the levels of exploited and taxed land.
Third, the distribution of the world's capital is hardly so tilted towards land as it used to be. Intellectual property, for instance, makes up much of the world's capital today- far more than in George's time. Likewise, debts, stocks, and other purely financial instruments make up a huge portion of rhe world's capital now. That doesn't even count the vast increase in non-land physical capital, which is huge. Simply put, land doesn't make up enough of the world's total capital to balance income inequality anymore.
Taken to its logical conclusion, Georgism might proceed to a general tax on capital. This is, of course, a singularly challenging task, especially given how illiquid much of it is. Not impossible, but somewhat impractical.
Also, as to Piketty's maturity or lack thereof- his real-world dataset is larger than the datasets used by the entirety of Georgist economists. (As well as a number of other economic disciplines.) Data in that quantity forgives a lot.
And as to income taxation being unfair- governance has never and will never be about fairness. It's about monopolizing force. The anarchists got that right, even if I disagree with a lot of other stuff they think and want.
The unimproved value of land is constrained by zoning and whatever improvements exist nearby. Can you tell me more about the topsoil damage in Australia that you mentioned?
Land value tax wouldn't be used on farmland or areas zoned for extraction (mines) as that would incentivise environmental degredation. It makes more sense to collect royalties on whatever was taken from the land.
Indeed, land is not the only economic privilege that contributes to inequality growth, but its significance shouldn't be downplayed. I recommend taking a look at this list of total resource rents by Prosper Australia to give an idea of what could be taxed instead of incomes.
Basically, Australia's spent the last couple centuries stripping their topsoil for sheep, cattle, and short term (1-generation or less) farms. They have the most garbage soil management program of any major industrial nation on the planet- and there are some bad ones. (The world's total topsoil loss in arable land over the 20th century amounts to over a third of the amount currently in production, so that says a lot.) Using Australia as an example for anything to do with land is highly suspect at best. Hell, the Prosper Australia site you linked me to even says "Under a land tax system, the rural sector would enjoy a lower tax burden, encouraging decentralisation." This could very directly contribute to even further worsening the topsoil of Australia. (If you're really interested, I highly recommend Montgomery's Dirt: The Erosion of Civilization.)
There's no practical difference in collecting tax on land and on resources extracted from land when it comes to historical environmental degradation. We have examples of both methods dating back to the Roman Empire- only direct controls on land use, like preserves and National Parks, prevent environmental degradation of the land.
You're conflating land tax (or land rent) with land use.
A land value tax would be the wrong thing for agricultural land because it would incentivise people to pillage as quickly as possible and exit so as to minimise their tax burden.
Collecting royalties is appropriate because you're charging people for what they've taken. The more they pillage the land, the more they have to pay. If anything, it's a disincentive!
I agree with you that the environment is extremely important and I believe that this can be achieved by managing resources with a long-term mindset. One of the things I love about permaculture is how they focus on building soil and rehabilitating land.