# Henry George Theorem The **Henry George Theorem** (HGT) is a result in urban public finance: under stated conditions, **aggregate differential land rents in a city equal expenditure on pure local public goods when city population is optimal.** A confiscatory tax on those rents is then not only non-distorting; it is also *sufficient* to finance those public goods. The name honors [[Henry George]]’s [[Single tax]]. The modern proof is Joseph Stiglitz (1977), developed with Richard Arnott in the *Quarterly Journal of Economics* (1979). ^def Arnott–Stiglitz: > [I]n a simple spatial economy, where the spatial concentration of economic activity is due to a pure local public good and where population size is optimal, aggregate land rents equal expenditure on the pure public good. This result has been dubbed the Henry George Theorem (HGT), since a confiscatory tax on land rents is not only efficient, it is also the “single tax” necessary to finance the pure public good. ## What “optimal population” is doing Think of a city that exists because of a shared public good (a port, a park system, a legal order). People crowd in. Congestion and rising land rents push back. At the population that maximizes per-capita welfare, the extra rent generated at the margin by one more resident lines up with the cost of the public good that made the city worth joining. Summed, rents = public-goods bill. The 1979 paper argues the result is robust in *large* economies where (i) the spatial allocation is Pareto optimal and (ii) differential land rents are well defined. Drop any condition and the single tax on differential rent may overshoot or undershoot. Congestion and other scale economies change the *which aggregates* identity, not the existence of a rent–public-goods link. ^conditions ## What it is not - Not a proof that U.S. federal spending can be funded by a national LVT. The theorem is about *local* public goods and *optimal-size* cities. - Not a claim that measured land rents in actual, oversized or undersized, zoned cities equal measured budgets. - Not the same as [[ATCOR]], which is about the incidence of *existing* taxes on labor and capital. HGT is about *new* amenity spending creating *new* rent. George himself asserted sufficiency as a political-economy claim (“the value of the land taken as a whole is sufficient to bear the entire expenses of government”). HGT is the later, narrower, formal cousin. ## Use and abuse Georgists cite HGT as the respectable-economics warrant for “tax the site, fund the city.” Skeptics reply: show the city is at optimum, show the good is pure and local, show differential rent is measurable — then talk sufficiency. Partial LVT can still be first-best *among available instruments* without the theorem holding as an equality. --- ## Citations 1. [Henry George theorem — Wikipedia](https://en.wikipedia.org/wiki/Henry_George_theorem). Stiglitz 1977; complementarity with ATCOR/EBCOR. 2. Joseph E. Stiglitz, “The Theory of Local Public Goods,” in *The Economics of Public Services*, ed. Feldstein & Inman (1977). 3. Richard J. Arnott & Joseph E. Stiglitz, “Aggregate Land Rents, Expenditure on Public Goods, and Optimal City Size,” *Quarterly Journal of Economics* 93(4) (1979): 471–500. [IDEAS/RePEc](https://ideas.repec.org/a/oup/qjecon/v93y1979i4p471-500..html). Quotation from the archived PDF introduction. 4. Alanna Hartzok, “Socializing Land Rent, Untaxing Production” (2013 PDF at cooperative-individualism.org). Stiglitz 1977 restated for a Georgist audience. 5. George’s sufficiency claim: *Progress and Poverty*, Book 8, via [explorepahistory excerpt](https://explorepahistory.com/odocument.php?docId=1-4-20B.html). 6. Related: [[ATCOR]], [[Single tax]], [[Land value tax]].