For decades, a pervasive narrative has dominated political discourse in the United States: the belief that the American tax code is insufficiently progressive, failing to extract a "fair share" from the nation’s wealthiest earners. However, a landmark study released by the Fraser Institute challenges this conventional wisdom, utilizing a comprehensive index of OECD economies to reveal a starkly different reality. Far from being a regressive outlier, the United States stands at the apex of international progressivity, operating what is arguably the most progressive tax system among developed nations.
The Fraser Institute Index: A New Benchmark for Progressivity
Measuring the progressivity of a tax system is an exercise fraught with complexity. Tax codes are rarely monolithic; they are labyrinths of statutory rates, exemptions, deductions, and credits. Furthermore, tax policy is frequently conflated with broader fiscal objectives, such as social welfare redistribution and transfer payments. To cut through this noise, researchers Grady Munro, Milagros Palacios, Nathaniel Li, and Jason Clemens of the Fraser Institute have developed a unique, multidimensional index.
The study evaluates 45 jurisdictions across 33 OECD countries, providing a systematic framework that isolates the design of the tax code itself. By focusing exclusively on how revenue is raised—rather than how it is spent—the index provides a rare, clear-eyed look at the distributional burden of taxation.
How the Index Works
The Fraser Institute’s methodology relies on five critical metrics, chosen for their comparability across diverse economic landscapes:
- Marginal PIT Rate Range: Assessing the gap between the lowest and highest statutory personal income tax rates.
- Distance to Top Tax Bracket: Measuring the income threshold required to reach the maximum rate.
- Low-Income Tax Protection: Evaluating the extent to which the lowest earners are shielded from the tax burden.
- Income Tax Share of Total Revenue: Determining the reliance on progressive income taxes versus other forms of revenue.
- Consumption Tax Share of Total Revenue: Accounting for the fact that lower consumption tax reliance is a key indicator of higher relative progressivity in a global context.
To ensure accuracy, the researchers sampled subnational authorities where local tax power is significant. In the United States, for instance, the study analyzed California—representing a high-tax, high-rate environment—and Texas, which levies no state-level personal income tax (PIT). This dual-sampling approach captures the nuance of American fiscal federalism, where the "average" tax burden is a blend of federal, state, and local mandates.
Chronology of the Debate: From Policy Reform to Modern Analysis
The debate over tax progressivity is not new, but the tools to measure it have evolved significantly.
- The Mid-20th Century: The post-war era was characterized by high marginal rates, which many assumed equaled high progressivity. However, as the tax code became increasingly riddled with "loopholes" and preferences, these statutory rates became less indicative of actual economic impact.
- The 1986 Tax Reform Act: This landmark U.S. legislation began a shift toward broadening the tax base while lowering rates, a move that critics feared would reduce progressivity but which ultimately simplified the code.
- The Modern Era: Since the early 2000s, economists have increasingly moved away from looking solely at "top rates." Instead, they have focused on "effective tax rates"—what people actually pay after all credits and deductions are applied.
- 2025 (The Current Study): The publication of the Fraser Institute’s research marks a pivot point. It shifts the focus back to the structure of the tax system as a whole, providing a comparative baseline that places the U.S. firmly at the top of the international leaderboard.
Supporting Data: Why the U.S. Ranks at the Top
The findings of the Fraser Institute are unequivocal: the U.S. is the most progressive jurisdiction in their 45-member sample. California, despite its unique economic pressures, ranks as the #1 most progressive jurisdiction globally. Texas, even without a state income tax, ranks an impressive 4th, trailing only Newfoundland & Labrador (Canada) and Korea.
The data reveals two primary drivers for this high standing:
- Income Tax Reliance: The U.S. ranks second only to Denmark in the share of total tax revenue derived from income taxes. Because income taxes are generally more progressive than consumption or payroll taxes, this reliance inherently boosts the U.S. score.
- Consumption Tax Absence: Most OECD nations rely heavily on Value-Added Taxes (VATs), which are often viewed as regressive because they hit lower-income consumption harder. Because the U.S. lacks a federal VAT, it avoids this regressive trap, ranking as the most progressive in the OECD regarding its consumption tax revenue share.
Addressing the Critics: Strengths and Weaknesses
No economic index is without its limitations. Critics of the Fraser study point to the exclusion of refundable tax credits as a potential blind spot. In the U.S., credits like the Earned Income Tax Credit (EITC) and the Child Tax Credit (CTC) are vital tools for low-income households. Because the index focuses on statutory structures, it may inadvertently undervalue these mechanisms, which play a larger role in the U.S. than in many European counterparts.
Furthermore, the study acknowledges that income reporting differences—specifically the rise of the "pass-through" sector in the U.S.—can skew the data. As more business income is reported on individual returns rather than corporate ones, the U.S. tax base appears more concentrated at the top. While this makes the tax system look more progressive, it also reflects a difference in how the U.S. classifies business entities compared to other nations.
Despite these nuances, the index is praised for its "purity." By excluding spending and welfare policies, it prevents the data from being masked by government redistribution. It isolates the tax system’s design, showing that the American architecture is inherently weighted to extract more from the top than from the bottom.
Implications for Policymakers
The implications for Washington are profound. If the U.S. tax code is already the most progressive in the developed world, then the impetus for "increasing progressivity" must be re-evaluated.
1. The Diminishing Returns of Marginal Rates
Policymakers often look to raise top marginal tax rates as a default solution for revenue or inequality concerns. However, the international data suggests that such moves may encounter the "Laffer Curve" effect: higher rates leading to increased avoidance and behavioral shifts, ultimately resulting in slower economic growth with negligible net revenue gains.
2. The Focus on Structural Efficiency
Rather than chasing higher rates, the study suggests that future reforms should focus on broadening the tax base and simplifying the code. The U.S. currently relies on a complex web of credits and deductions to achieve equity. A more efficient system might rely on lower, flatter rates that maintain the existing progressive structure while reducing the compliance burden on taxpayers.
3. Global Context Matters
The "fair share" debate often occurs in a vacuum. By viewing the U.S. within the context of the OECD, lawmakers can better understand the trade-offs involved in global tax competition. As other nations move toward flatter tax structures or consumption-based models to stimulate investment, the U.S. must ensure that its high-progressivity model does not stifle the capital formation necessary to maintain its global economic edge.
The Bottom Line
The Fraser Institute’s study serves as a necessary reality check for the American political establishment. While it is true that income inequality is a significant issue in the United States, the data indicates that the tax code itself is not the source of the problem. On the contrary, the U.S. tax structure is a highly sophisticated, highly progressive machine that already places a significant burden on the nation’s highest earners.
As policymakers prepare for future fiscal debates, they should approach the concept of "progressivity" with the nuance it deserves. The goal of fiscal policy should be to balance the need for revenue with the necessity of growth. In doing so, they might find that the U.S. system is already doing exactly what it was designed to do: asking those with the most to contribute the most, a standard that, by international measures, the United States has mastered.
