How We Verify

How We Verify

This is a reference built to be argued with. If you are going to quote it in public, brief a policymaker from it, or use it to check someone else's claim, you should first know how we decide what to say and how confident we are when we say it. This page states that standard plainly.

The short version: the wiki is meant to be persuasive because it is accurate, well-sourced, and fair — never because it asserts a conclusion. A reader who disagrees with Georgism should still be able to see that their strongest objection has been understood, sourced, and answered rather than dodged.

Every sentence is a graded claim

We do not treat all statements alike. Each substantive sentence is classified and sourced according to what kind of claim it is:

• Factual / historical claims — dates, people, what a report actually concluded — need a reliable source, and where the exact wording carries weight we quote the primary text.
• Empirical claims — effects, magnitudes, who bears a tax, what happened when a policy was tried — must rest on the best available evidence: peer-reviewed work, official datasets, government reports. We do not present a finding as settled unless the literature is.
• Theoretical claims — that a tax on land is efficient, that public investment capitalizes into land value — are stated as claims with their assumptions attached, distinguishing "the theorem states," "proponents argue," and "critics dispute."
• Interpretive and argumentative claims — "the strongest case for land-value taxation is…" — are either attributed to a source that makes the argument or explicitly framed as our own analysis. We never dress interpretation as fact.
• Objections get the strongest real version: a serious academic critique, an opposing policy paper, a documented implementation failure. No strawmen.

Claim pages carry an evidence grade on their face — Strong, Moderate, Emerging, Contested, or Theoretical — and the first screen shows the claim, its three strongest citations, and one honest-limits line, so you can quote it in thirty seconds and not get burned.

We check the sources, not just list them

A citation is attached to the specific claim it supports, not dumped in a footer. Where a source is used, it is checked:

• Quotes are verified verbatim against the primary text. When a page attributes words to an economist or a report, we confirm those words. This wiki has corrected its own misattribution — a paraphrase carrying the theme of Cabral & Hoxby's work on the property tax was flagged and traced back to what the primary source actually says, rather than left standing.
• Figures are checked against the primary, and the primary wins. When our number and the source disagree, the source is authoritative. We caught and corrected a transposition that had rendered Barr, Smith & Kulkarni's Manhattan land-value estimate as $1.74 trillion; the paper says $1.47 trillion, and the page now says $1.47 trillion.
• When a number cannot be verified, it comes out. A frequently repeated "2% of GDP" figure that no primary source could be found to support was removed rather than kept for being convenient. We would rather have a gap than an unsourced claim.

Sources are ordered by evidential weight, strongest first: top-journal and quasi-experimental work ahead of other peer-reviewed work, ahead of official reports, ahead of working papers, ahead of advocacy. A reader who reads only the first citation should have met the best one.

When we can't confirm it, the page says so

The rule we hold hardest: we never fabricate. No invented source, quote, author, date, page number, or URL. When we cannot find a source for a claim, the page carries a visible marker saying exactly what is missing — an honest gap a reader can see, not a confident sentence hiding an absence. Claims that outrun their evidence are softened or flagged for review. This is the honest-stop rule, and it is why unfinished corners of the wiki are labelled rather than papered over.

The rent gradient: certainty is not uniform

Georgism's core case is about land, and land is the clean case — supply is fixed, there is no production incentive to damage, and a century of incidence evidence stands behind it. That case can be stated strongly because the evidence is strong.

Every step away from land is more contested, and pages must say so. Resource rents mix with extraction incentives; "monopoly rents" may partly be efficiency returns; innovation profits are largely the quasi-rents that are the incentive to innovate, so taxing them is not costless the way taxing location is. The wiki carries these disputes openly and never lets the airtight land case lend its certainty to the contested frontier.

Evidence is wired to all three lanes — including against us

Research on this wiki is connected to the problems it diagnoses, the benefits it measures, and the objections it bears on. Crucially, that wiring runs both ways: when a study strengthens an objection to Georgism, it is linked on the objection's steelman side, not buried. The reader is meant to find the counter-evidence in the same place as the evidence.

How to report an error

This wiki is version-controlled and public. If you find a misquote, a bad figure, a dead link, or a claim that has outrun its source, open an issue or a pull request on the GitHub repository. Corrections are how the record improves, and the ones described above all began as someone noticing.

See Also

• Start Here — the entry point for advocates and policymakers
• Georgism — the philosophy this wiki documents
• Economic Rent — the concept at the center of the rent gradient