As Congress wrestles with the expiration of the 2017 Tax Cuts and Jobs Act, one provision has provoked an unlikely bipartisan coalition: the $10,000 cap on state and local tax (SALT) deductions. Legislators from New York, New Jersey, California, and Illinois — states that span both parties — are pressing to raise or eliminate the cap. The policy argument they advance is framed as tax fairness. But there is a different argument that rarely gets made: restoring full SALT deductions would amount to a federal subsidy for the very fiscal and regulatory architecture that has made housing in America catastrophically unaffordable.
What the SALT Deduction Is — and What It Actually Does
The state and local tax deduction allows taxpayers who itemize their federal returns to deduct property taxes plus either state income taxes or state sales taxes from their federal taxable income. Before 2018, this deduction was unlimited. The Tax Cuts and Jobs Act capped it at $10,000 per household for tax years 2018 through 2025. With TCJA now expired, the future of SALT policy sits squarely in Congress's hands.
The deduction's practical effect is straightforward: it reduces the after-tax cost of living in a high-tax state. When your state collects $20,000 in income and property taxes, a full SALT deduction means the federal government absorbs a portion of that bill through reduced federal tax liability. The higher your state and local taxes, the larger the federal subsidy — effectively a transfer from taxpayers in low-tax states to those in high-tax ones.
The Geography of SALT: A Concentrated Benefit
The SALT deduction has never been a broadly distributed benefit. According to Internal Revenue Service data analyzed by the Tax Foundation, just seven states — California, New York, Texas, New Jersey, Maryland, Illinois, and Florida — claimed more than half of all SALT deductions nationwide in 2018. California alone accounted for 19.8 percent of all SALT deductions taken across the entire country.
The distribution skews heavily toward higher earners. In 2020, only 9.5 percent of all taxpayers itemized, meaning only that fraction could access the SALT deduction at all. Among those earning $500,000 or more annually, however, 70 percent itemized. The deduction is structurally a benefit for the upper-income households concentrated in high-cost coastal metros — not the working families whose housing costs have become untenable.
The state-level fiscal picture reinforces this concentration. According to Tax Foundation analysis of FY 2022 Census Bureau data, New York residents carry the second-highest combined state and local tax burden in the nation at $12,685 per capita. California follows at $10,319. The national average is $7,109. At the other end of the spectrum: Alabama at $4,722 and Tennessee at $4,731. A full SALT deduction would cost approximately $226 billion in federal revenue in just two years — a subsidy flowing predominantly to these same high-burden states.
The Housing Connection: A Correlation That Isn't Random
Consider the overlap: the states that benefit most from SALT deductions are the same states with the worst housing affordability in the nation. California, New York, New Jersey, Connecticut, and Illinois consistently rank among the least affordable housing markets by any measure — median price-to-income ratio, homeownership rate among younger households, or residential permit output relative to population growth.
This is not merely a geographic coincidence. It reflects a common underlying cause: high-tax, high-spending state and local governments tend also to be the governments that impose the most severe restrictions on housing supply. Extensive environmental review requirements, mandatory inclusionary zoning, lengthy permitting timelines, and politically entrenched NIMBY constituencies are disproportionately features of the same jurisdictions that generate the largest SALT deduction claims.
Milton Friedman's framework for understanding government intervention offers a clarifying lens here. In his analysis of tax deductions as hidden subsidies, Friedman argued that any federal deduction is functionally equivalent to a federal expenditure — the government simply collects less from the taxpayer rather than writing a direct check. Under this framework, the SALT deduction is an annual federal expenditure subsidizing the governance structures of high-tax states. Washington is, in effect, writing a check every year to make it cheaper to live under the regulatory regimes that have priced millions of Americans out of homeownership.
The Moral Hazard: Insulating Failure from Its Consequences
This is where the housing policy implications become structural rather than merely correlational. Friedrich Hayek's concept of dispersed knowledge — the idea that market prices aggregate information that no central planner possesses — applies directly to the feedback mechanism that SALT disrupts.
In a world without SALT deductibility, residents of high-tax, restrictive-zoning states bear the full cost of their government's choices. Housing costs are high, taxes are high, and the combined burden creates real pressure for reform. People and businesses migrate to lower-cost jurisdictions — a market signal that something is wrong. Thomas Sowell described this process as the "spontaneous order" of market correction, where outcomes signal misallocation without requiring any central coordinator.
The SALT deduction mutes that signal. By partially offsetting the cost of high-tax governance through federal tax relief, it reduces the net burden on high-income households — exactly the households whose political engagement and local influence most shape zoning decisions. A homeowner whose $20,000 in state and local taxes is substantially deductible against federal income has less fiscal incentive to demand that local government stop blocking new housing construction, streamline permitting, or eliminate exclusionary zoning. The federal government is, perversely, subsidizing the political coalition that manufactures housing scarcity.
The Comparison the SALT Debate Rarely Makes
Proponents of restoring the SALT deduction rarely engage with the counterfactual: states without income taxes, and therefore with minimal SALT exposure. Tennessee and Florida, which impose no personal income tax, have historically attracted substantial population migration and tend to produce housing at higher rates relative to population than New York or California. Texas, also income-tax-free, added more housing units per capita than any major high-SALT state over the past decade.
The causal chain is not that low-tax states automatically produce abundant housing — Texas has its own land-use challenges, particularly in its major metros. But the fiscal model of low-tax, lower-regulation governance creates conditions in which housing supply can respond to demand. When government consumes less in taxes and imposes fewer process requirements, the marginal cost of building falls, and developers respond accordingly. The SALT deduction, by contrast, reduces the political pressure on high-tax states to adopt any such reforms.
What Real Reform Would Signal
Maintaining the SALT cap — or going further and eliminating the deduction entirely, as Tax Foundation analysis suggests would raise approximately $2 trillion over a decade — would force a different kind of reckoning. State and local governments in California, New York, and New Jersey would face taxpayers bearing the full weight of their fiscal choices. The demand for regulatory streamlining, faster permitting, and pro-supply zoning reform would intensify — because the federal safety valve that has cushioned high-tax governance would no longer exist.
This is not a promise that lower SALT deductibility alone solves the housing crisis. The supply constraints in high-cost metros are deep, legally entrenched, and resistant to change even when fiscal pressure mounts. But any serious analysis of housing affordability must reckon with the federal policy architecture that has made it rational, even comfortable, for state and local governments to sustain the regulatory regimes producing that crisis.
The SALT debate is almost always framed as a question of tax fairness. It is also, inescapably, a question of housing policy. When Congress chooses to subsidize high-tax governance through the federal tax code, it is choosing — however indirectly — to subsidize the institutional conditions that price working families out of homeownership. That is a choice worth naming plainly.
