Tax cuts pay for themselves through economic growth

The claim

Lowering tax rates does not reduce government revenue because it stimulates enough additional economic activity — investment, hiring, consumer spending — to expand the tax base. This is the Laffer Curve argument: there exists a revenue-maximizing tax rate, and the US is already above it, meaning cuts are self-financing. Proponents cite the Reagan expansion of the 1980s and the post-TCJA growth of 2018–2019 as confirmation.

The mechanism

The Laffer Curve is theoretically unassailable at its poles: a 0% tax rate produces zero revenue; a 100% tax rate also produces near-zero revenue because all economic activity ceases. A revenue-maximizing rate exists somewhere between these extremes. The argument fails not at the level of theory but at the level of application: the claim requires that current US rates are above the revenue-maximizing point, and that the behavioral response (increased investment, labor supply, and capital repatriation) is large enough to offset the mechanical revenue loss from the rate reduction.

Neither condition holds at rates typical of contemporary US tax policy. The revenue-maximizing rate for a broad-based income tax is generally estimated in the range of 50–70% of taxable income (Diamond & Saez, 2011, Journal of Economic Perspectives), well above the top marginal rates of 37% (post-TCJA) or 39.6% (Clinton-era). At these rates, behavioral responses generate additional revenue — but not enough to offset the mechanical loss.

The Joint Committee on Taxation (JCT) is the official congressional scoring body for tax legislation. It produces both conventional scores (mechanical revenue loss) and dynamic scores (incorporating macroeconomic feedback). In its dynamic score of the TCJA (2017), the JCT found that macroeconomic feedback effects offset approximately $450 billion of the $1.9 trillion gross revenue loss over ten years — leaving a net deficit addition of roughly $1.5 trillion. This is the most empirically credible estimate available: it was produced by a body with bipartisan oversight, using a transparent methodology, with access to the full legislative text. The claim of self-financing fails even with macroeconomic feedback fully credited.

The evidence

The Kansas experiment, 2012–2017

In 2012, Governor Sam Brownback signed the largest income tax cut in Kansas history, eliminating income taxes entirely for most small businesses (pass-through entities) and cutting the top individual rate from 6.45% to 3.9%. Brownback called it a “real-time experiment” in supply-side economics. The results:

• FY2013 income tax revenue fell 10.8% year-over-year
• FY2014 revenue fell a further 11.1%
• The state ran a $700 million deficit by FY2014
• Moody’s downgraded Kansas’s credit rating twice (2014, 2016)
• The state cut K-12 education funding; the Kansas Supreme Court ruled the cuts unconstitutional in 2016
• In 2017, the Republican-controlled legislature overrode Brownback’s veto to reverse the cuts

The Kansas experiment is the closest the US has to a controlled test of supply-side theory. The prediction was accelerated growth and self-financing revenue. The outcome was a fiscal crisis severe enough that the experiment’s own governing party abandoned it within five years.

Reagan, 1981–1989

The Reagan tax cuts (Economic Recovery Tax Act, 1981) reduced the top marginal rate from 70% to 50%, then the Tax Reform Act of 1986 reduced it further to 28%. The national debt:

• 1981: $994 billion (32% of GDP)
• 1989: $2.9 trillion (53% of GDP)

Revenue as a share of GDP fell from 19.6% in 1981 to 17.5% in 1984, then partly recovered — but the recovery followed two tax increases (Tax Equity and Fiscal Responsibility Act, 1982; Deficit Reduction Act, 1984), not further supply-side stimulus. The Reagan expansion was accompanied by a tripling of the national debt. OMB Historical Tables confirm these figures.

The Bush tax cuts, 2001–2008

The Economic Growth and Tax Relief Reconciliation Act (2001) and Jobs and Growth Tax Relief Reconciliation Act (2003) cut the top marginal rate from 39.6% to 35% and reduced capital gains and dividend rates. The surplus that existed in 2000 ($236 billion) became a $1.4 trillion deficit by 2009. The CBO’s retrospective analysis attributed approximately $1.6 trillion of the 2001–2008 fiscal deterioration to the tax cuts (roughly half of the total fiscal change). GDP growth in the 2001–2007 expansion was slower than in the 1990s expansion that followed the 1993 Clinton tax increase.

Clinton 1993 tax increase and subsequent growth

The Omnibus Budget Reconciliation Act of 1993 raised the top marginal rate from 31% to 39.6% over strong Republican opposition, with predictions that it would produce recession. The subsequent record:

• The 1990s expansion ran 120 months (longest peacetime expansion on record at the time)
• The federal budget moved from a $290 billion deficit in 1992 to a $236 billion surplus in 2000
• Real GDP grew at 3.5% per year from 1993 to 2000

This is the mirror image of the supply-side prediction: rates increased, the economy accelerated, and revenue rose sharply as a share of GDP. Supply-side proponents argue other factors explain the 1990s boom (technology, globalization, Federal Reserve policy). The same argument — that confounding factors explain the apparent disconnect — applies symmetrically to all claimed supply-side successes.

TCJA 2017 and the CBO/JCT scorecard

The Tax Cuts and Jobs Act of 2017 reduced the corporate rate from 35% to 21% permanently and cut individual rates temporarily (expiring 2025). The JCT dynamic score estimated a net $1.46 trillion deficit increase over ten years. Actual data through 2023 is consistent with this projection:

• Federal corporate income tax revenue fell from $297 billion (FY2017) to $205 billion (FY2018), a 31% one-year drop
• The federal deficit widened from $665 billion (FY2017) to $984 billion (FY2019, pre-COVID), despite low unemployment
• GDP growth in 2018 (2.9%) and 2019 (2.3%) was not substantially above the pre-TCJA trend, and did not produce the revenue feedback that self-financing requires

OECD cross-national evidence

If high taxes suppress growth, high-tax nations should grow more slowly. The evidence from OECD data does not support this:

• Denmark: tax revenue 46.4% of GDP (2022); average annual real GDP per capita growth 2000–2022: 0.9%
• Sweden: 42.6%; 1.4% average growth
• Germany: 39.3%; 1.0% average growth
• France: 45.1%; 0.7% average growth
• United States: 27.7%; 1.2% average growth
• Canada: 33.2%; 1.0% average growth

The US does not grow faster than its higher-taxed peers by a margin consistent with the large growth effects required for self-financing. The cross-national pattern shows no strong negative relationship between aggregate tax burden and long-run growth rate.

Who benefits

The primary financial beneficiaries of income and corporate rate cuts are high-income households and large corporations. The Tax Policy Center estimated that the top 1% of households received 20.5% of TCJA benefits; the top quintile received 65.3%. Corporations received permanent rate reductions while worker cuts were temporary and smaller in dollar terms.

The institutional infrastructure promoting self-financing claims is largely funded by these beneficiaries. The Heritage Foundation, American Enterprise Institute, and Cato Institute receive major funding from the Koch network and other high-net-worth donors with direct financial interests in rate reductions. The supply-side consensus within these institutions is not independent of their funding base. Art Laffer himself earned substantial consulting fees from state governments, including Kansas, for advocating the policies that subsequently failed. The National Federation of Independent Business, whose small-business members benefited directly from the Kansas pass-through elimination, was among the strongest advocates.

The counter

Supply-side economics is not entirely without empirical foundation. High marginal rates at very elevated levels do produce behavioral responses: the evidence on tax avoidance and income shifting at rates above 60–70% is reasonably strong. The Laffer Curve framework is correct in principle. The contested empirical question is whether current US rates are on the right or left side of the revenue-maximizing point.

Some economists argue that dynamic scoring by the JCT and CBO uses models with behavioral elasticities calibrated from older literature, and that more recent estimates of the taxable income elasticity (Chetty, 2012) imply somewhat larger behavioral responses than official models assume. If elasticities are higher than official estimates, revenue offsets from tax cuts are also higher — though even the most generous mainstream estimates do not produce full self-financing at US rates.

The supply-side literature also correctly identifies that the composition and structure of taxation matters, not just the level. Base-broadening, loophole-closing tax reforms (like the 1986 Tax Reform Act) can raise revenue and improve efficiency simultaneously. This more careful argument — that poorly designed taxes with high rates and narrow bases are worse than well-designed taxes with lower rates and broad bases — is not the same as the strong claim that tax cuts self-finance. Conflating the two has been the central rhetorical strategy of supply-side advocates since 1981.

References

Blanchard, O., & Leigh, D. (2013). Growth forecast errors and fiscal multipliers. American Economic Review, 103(3), 117–120. https://doi.org/10.1257/aer.103.3.117

Congressional Budget Office. (2018). The budget and economic outlook: 2018 to 2028. https://www.cbo.gov/publication/53651

Diamond, P., & Saez, E. (2011). The case for a progressive tax: From basic research to policy recommendations. Journal of Economic Perspectives, 25(4), 165–190. https://doi.org/10.1257/jep.25.4.165

Joint Committee on Taxation. (2017). Macroeconomic analysis of the Tax Cuts and Jobs Act as passed by the Senate (JCX-62-17). https://www.jct.gov/publications/2017/jcx-62-17/

Kansas Legislative Research Department. (2017). Kansas tax policy: Legislative history and fiscal analysis 2012–2017. Kansas Legislature.

Krugman, P. (2019). Arguing with zombies: Economics, politics, and the fight for a better future. W. W. Norton. (Chapter on supply-side economics and the Laffer Curve)

Samuelson, P. A., & Nordhaus, W. D. (2010). Economics (19th ed., pp. 344–347). McGraw-Hill. (Discussion of Laffer Curve empirical limits)

Saez, E., Slemrod, J., & Giertz, S. H. (2012). The elasticity of taxable income with respect to marginal tax rates: A critical review. Journal of Economic Literature, 50(1), 3–50. https://doi.org/10.1257/jel.50.1.3

Slemrod, J. (1995). Income creation or income shifting? Behavioral responses to the Tax Reform Act of 1986. American Economic Review, 85(2), 175–180.

U.S. Office of Management and Budget. (2024). Historical tables, Budget of the United States Government, FY2024, Table 7.1: Federal debt at the end of year. https://www.whitehouse.gov/omb/budget/historical-tables/