What Is the Laffer Curve? Tax Rates and Revenue Explained
By Markets & Investing DeskUpdated Nov 10, 2026
Definition
The Laffer curve models how tax revenue changes with the tax rate. Revenue is zero at 0% and at 100%, and it peaks at a rate in between, past which further increases collect less.
Key takeaways
- Below the peak rate, a tax cut loses revenue even if it encourages some extra economic activity.
- With a constant elasticity of taxable income e, the revenue-maximizing rate equals 1 divided by (1 + e).
- An elasticity of 0.25 puts the peak at 80%, while an elasticity of 2.0 puts it at about 33%.
- A tax cut can be partly self-financing, but revenue only rises if self-financing tops 100%.
The Laffer curve is an economic model of the relationship between a tax rate and the revenue it raises. It holds that revenue is zero at a 0% rate and also at a 100% rate. Somewhere in between sits a rate that collects the most money. Above that rate, raising taxes further shrinks the tax base so much that total revenue falls, and cutting the rate could raise revenue. Below it, a tax cut loses revenue, even if it encourages some extra activity.
How the Laffer curve works
Any tax raises revenue equal to the rate multiplied by the base it applies to: income, profits, sales, gallons of fuel, bottles of wine. Laffer’s point was that the base is not fixed. When the rate rises, people and businesses change their behavior. They may work fewer hours, invest less, shift income into lower-taxed forms, use legal deductions more aggressively, move activity abroad or into the informal economy, or simply buy less of the taxed product.
Two forces therefore pull in opposite directions when a rate changes:
- The arithmetic effect. At a given base, a lower rate collects less per dollar of base. Every dollar of tax cut is a dollar less revenue, immediately.
- The economic effect. A lower rate leaves taxpayers with more after-tax income and raises the reward for working, saving and investing. If activity grows, the base grows, which offsets part of the arithmetic loss over time. Laffer also emphasized the spending side: taxpayers who keep more of their income spend it, which supports business activity and employment.
At low rates the arithmetic effect dominates, so raising the rate brings in more money. As the rate climbs, behavioral responses get stronger, because each extra point takes a larger share of what the taxpayer would otherwise keep. At some point the base shrinks faster than the rate rises, and revenue turns down.
Reading the graph
The horizontal axis shows the tax rate from 0% to 100%. The vertical axis shows total revenue. The curve rises from zero, peaks at T*, and falls back to zero at 100%. The endpoints follow from the definition: at 0% the government collects nothing, and at 100% there is no reason to earn income in the formal economy, so the base collapses.
- Left of T (normal range):* raising the rate increases revenue; cutting it reduces revenue.
- At T:* revenue is at its maximum. A small change in either direction lowers it.
- Right of T (prohibitive range):* raising the rate reduces revenue; cutting it increases revenue.
Except at the peak, two different rates can raise the same revenue: a low rate on a large base and a high rate on a small base. Stylized drawings often put the peak at 50%, but the real curve need not be symmetric, and its peak can sit well to either side of the middle.
Calculating the revenue-maximizing rate
Revenue = t × B(t)
where t is the tax rate and B(t) is the taxable base, which shrinks as t rises. The shape of B(t) decides where the peak falls.
A common simplified approach uses the elasticity of taxable income, written e. It measures how much the base responds, in percentage terms, to a change in the share of each dollar the taxpayer keeps (1 − t). Under the assumption that this elasticity is constant, the revenue-maximizing rate is:
T = 1 / (1 + e)*
Hypothetical values show how sensitive the answer is:
| Assumed elasticity (e) | Revenue-maximizing rate (T*) |
|---|---|
| 0.25 | 80% |
| 0.5 | about 67% |
| 1.0 | 50% |
| 2.0 | about 33% |
A small base response puts the peak at a very high rate. A large response puts it much lower. Economists who agree on the formula can still reach very different conclusions because they disagree about e. Applied versions add complications: the elasticity varies across income groups, and a higher rate on one tax can reduce revenue from others.
Worked example
Hypothetical: a government taxes a base that would be $1,000 with no tax. Assume the base shrinks in direct proportion to the rate, so B(t) = $1,000 × (1 − t). This corresponds to e = 1, so T* should be 50%.
| Tax rate | Taxable base | Revenue |
|---|---|---|
| 0% | $1,000 | $0 |
| 30% | $700 | $210 |
| 50% | $500 | $250 |
| 70% | $300 | $210 |
| 100% | $0 | $0 |
Revenue peaks at $250 when the rate is 50%. A cut from 70% to 50% raises revenue from $210 to $250, a Laffer effect. A cut from 50% to 30% lowers revenue from $250 to $210, even though the base grows by $200. The 30% and 70% rates raise identical revenue, which shows the two-rates property.
Static vs. dynamic analysis
Static analysis assumes the base stays the same. Cutting a rate from 30% to 25% on a $100 billion base is scored as a $5 billion revenue loss. It captures only the arithmetic effect.
Dynamic analysis adds estimated behavioral and economic responses, such as changes in work, investment, reported income and GDP. It captures the economic effect as well.
The share of the static revenue loss that dynamic effects win back is sometimes called the degree of self-financing. If a cut’s static cost is $5 billion and growth and behavioral changes recover $1.5 billion, the cut is 30% self-financing. A true Laffer effect, in which revenue rises after a cut, requires self-financing above 100%, which only happens in the prohibitive range. A tax cut can be partly self-financing without being on the downward slope of the curve.
History of the Laffer curve
The basic idea predates Laffer, who acknowledged his predecessors. The 14th-century historian Ibn Khaldun wrote that low tax rates early in a dynasty produced large revenues while high rates later produced small ones, and John Maynard Keynes observed that taxation could be so high that it defeated its own purpose.
The modern version dates to 1974, when Laffer presented the argument to members of President Gerald Ford’s administration, reportedly sketching the curve on a napkin at a Washington restaurant. Against the prevailing view that higher rates meant higher revenue, he argued that heavy taxation reduces business investment, pushes firms to shelter capital or move abroad, and weakens workers’ incentive to earn more. Journalist Jude Wanniski named the idea the “Laffer curve” and promoted it widely.
Reaganomics
The curve became a central argument for the supply-side policies of President Ronald Reagan, often called Reaganomics. The Economic Recovery Tax Act of 1981 cut marginal income tax rates sharply, and the Tax Reform Act of 1986 lowered the top rate further while broadening the base.
Federal tax revenue grew from about $517 billion in 1980 to about $909 billion in 1988, and inflation and unemployment fell. Other factors drove part of that growth: the figures are nominal, so some of the increase reflects inflation; population and the economy were growing; and several tax increases were enacted, including the 1982 tax act and the 1983 Social Security payroll tax changes. Separating the rate cuts’ effect from these factors is exactly where economists disagree.
How the Laffer curve is used
In tax debates, supporters of rate cuts cite the curve to argue that high rates discourage the work and investment that drive growth. Critics use the same framework to argue that current rates sit in the normal range, so cuts would reduce revenue.
The revenue-maximizing rate is also not the same as the best rate. A government may prefer to tax below T* because the last few points of revenue before the peak come with large losses of economic activity, or it may choose a high rate for other reasons, such as reducing inequality or discouraging a harmful product. The curve measures only revenue; weighing what that revenue costs is a separate opportunity cost question.
The Laffer curve for alcohol and other excise taxes
The logic is especially visible with excise taxes on alcohol, tobacco and similar products. A higher per-unit tax raises revenue per bottle or pack, but the base can shrink through lower consumption, cross-border shopping, smuggling and untaxed home production, so past some point a higher rate collects less. A shrinking base is often part of the purpose: a government that raises alcohol taxes to cut drinking may accept lower revenue, or even prefer it, so being on the downward slope is not automatically a policy failure.
Limitations of the Laffer curve
It uses a single tax rate. Real tax systems combine progressive income brackets, payroll, corporate, capital gains, sales and excise taxes. Cutting one can change revenue from others, for example when people reclassify wages as capital gains. A two-dimensional curve cannot capture those interactions.
T is not fixed.* The peak depends on the type of tax, how easy it is to avoid, how mobile the taxpayers are, the state of the economy and the time horizon, and short-term responses may differ greatly from long-term ones. A rate in the normal range in one country or decade can be prohibitive in another.
Behavior can run either way. The curve assumes higher taxes reduce effort. Economists distinguish the substitution effect (each hour of work pays less after tax, so people work less) from the income effect (people work more to keep their after-tax income from falling). Which dominates varies by person and situation. Businesses also weigh workforce skills, infrastructure, markets and other factors of production, not just tax rates.
Other forces can block the growth effect. Whether a tax cut stimulates activity depends on how long growth takes to appear, the size of the underground economy, how loopholes channel the response, and underlying productivity.
Laffer curve vs. supply-side and trickle-down economics
- The Laffer curve is a narrow claim about tax rates and revenue.
- Supply-side economics is a broader school holding that growth comes mainly from improving incentives to produce through lower marginal tax rates and less regulation. The Laffer curve is one of its arguments.
- Trickle-down economics is a critics’ label, not a theory economists use to describe their own work. It refers to policies that give tax breaks mainly to corporations and high earners on the expectation that the benefits will reach everyone else. The label was applied both to Herbert Hoover’s Depression-era measures and to the Reagan tax cuts.
FAQs
Has the Laffer curve been debunked?
No. The core logic is widely accepted: revenue is zero at 0% and 100%, so a peak must exist in between. The dispute is empirical: where specific taxes sit relative to that peak and how large behavioral responses are. Accepting the curve does not mean accepting that a particular tax cut will raise revenue, only that it can when the starting rate is above T*.
The Bottom Line
The Laffer curve matters to anyone weighing claims that tax cuts pay for themselves. Cutting a rate raises revenue only when that rate sits in the prohibitive range, and economists disagree on where the peak falls because they disagree about how strongly the tax base responds. The revenue-maximizing rate is also not automatically the best rate, since governments may tax above or below it for other goals.
