For decades, a central pillar of American political discourse has been the assertion that the U.S. tax code is insufficiently progressive, failing to adequately tax the wealthy while placing an undue burden on the middle and working classes. However, a groundbreaking new study from the Fraser Institute challenges this conventional wisdom. By utilizing a comprehensive, multi-metric index to analyze tax systems across the Organisation for Economic Co-operation and Development (OECD), researchers have concluded that the United States maintains the most progressive tax structure of the 33 developed nations examined.
This study arrives at a pivotal moment in global fiscal policy, offering a data-driven rebuttal to the narrative that the U.S. has fallen behind its international peers in ensuring those with the highest ability to pay shoulder the largest share of the tax burden.
The Challenge of Measuring Fiscal Progressivity
Defining and measuring "progressivity" is notoriously difficult. Tax codes are inherently complex, filled with overlapping deductions, credits, and exemptions. Furthermore, they are often conflated with broader redistribution policies, such as social safety nets, transfer payments, and government spending programs.
The Fraser Institute’s research, titled Measuring Progressivity in High-Income Countries, seeks to disentangle these variables. By focusing exclusively on tax design rather than the final outcomes of fiscal redistribution, the study provides a "cleaner" look at how different governments choose to extract revenue from their citizens. To achieve this, the authors constructed an index using five distinct metrics that are both measurable and comparable across diverse tax jurisdictions.
How the Index Measures Progressivity
The study evaluated 45 jurisdictions across 33 OECD countries, accounting for significant variations in subnational tax authority. In the U.S., the researchers sampled California and Texas to represent the spectrum of American tax policy—California featuring high state-level income taxes and Texas maintaining no state-level personal income tax (PIT).
The index relies on five key pillars:
- Marginal PIT Rate Range: Measuring the spread between the lowest and highest statutory tax brackets.
- Distance to Top Tax Bracket: Assessing how quickly a taxpayer reaches the maximum rate relative to average wages.
- Low-Income Tax Protection: Evaluating the value of standard deductions and exemptions for the lowest earners.
- Income Tax Share of Revenue: Analyzing how heavily a country relies on personal income taxes versus other forms of revenue.
- Consumption Tax Share of Revenue: Measuring the reliance on regressive consumption taxes (such as Value-Added Taxes, or VAT).
Chronology of the Debate: From Rhetoric to Data
The perception that the U.S. tax code is "regressive" or "flat" has been a staple of campaign rhetoric since the mid-20th century. During the 1980s and 90s, tax reform efforts often focused on simplifying the code, which critics frequently characterized as a "giveaway to the rich."
However, as the 21st century progressed, the availability of granular tax data from the Congressional Budget Office (CBO) and international bodies like the OECD allowed for more sophisticated longitudinal studies. The 2025 Fraser Institute study represents the culmination of this trend, moving away from purely political claims toward a standardized, comparative index. By excluding nations with insufficient data—such as Chile, Colombia, and Turkey—the researchers ensured that the comparison remained robust and consistent across stable, high-income economies.
Supporting Data: California and Texas in the Global Context
The results of the ranking are striking. California holds the top spot for progressivity among all 45 jurisdictions studied, while Texas ranks fourth, trailing only Newfoundland & Labrador (Canada) and Korea.
The U.S. advantage in these rankings is driven largely by its tax mix. While most European nations rely heavily on Value-Added Taxes (VAT)—which are inherently consumption-based and often regressive—the U.S. stands as an outlier. Because the United States lacks a federal consumption tax, its revenue structure is far more heavily weighted toward personal income taxes. In the "consumption tax share" metric, the U.S. ranks as the most progressive in the OECD, simply because it collects the lowest share of revenue through these mechanisms.
Furthermore, in the "income tax share of total tax revenue" category, the U.S. trails only Denmark. This combination of high reliance on income taxes and low reliance on consumption taxes creates a structural tilt that is inherently more progressive than the models utilized by most of America’s economic peers.
Understanding the Nuances: Strengths and Weaknesses
While the Fraser Institute index is a landmark study, it is not without its limitations. Transparency in methodology is key to understanding both what the study captures and what it leaves behind.
The Strengths of Isolation
The primary strength of the study is its focus on tax design rather than fiscal incidence. By ignoring government spending and welfare transfers, the index allows policymakers to isolate the specific impact of tax law. This is vital because two countries might achieve the same level of wealth redistribution—but one may do it through a highly progressive tax code, while another may do it through a flat tax combined with massive social spending. Understanding which lever is being pulled is essential for crafting effective future policy.
The "Missing" Impact of Tax Credits
Critics of the index point to its treatment of tax credits as a potential blind spot. The study relies primarily on statutory tax rates and standard deductions. In the United States, refundable tax credits (such as the Earned Income Tax Credit) are a major driver of effective progressivity. Because the index does not fully account for these credits, it may actually underestimate the degree of progressivity in the American system. Furthermore, because credits reduce total tax revenue, they can sometimes cause a system to appear "less progressive" under the index’s specific revenue-share metrics, creating an unintended statistical irony.
Income Reporting and the Pass-Through Sector
Another challenge in international comparison is the treatment of business income. In the U.S., a massive portion of the economy operates through "pass-through" entities—businesses that report income on individual tax returns rather than corporate ones. This shifts a large amount of taxable income into the individual tax code, which can make the U.S. appear to have a higher concentration of income at the top than it might in a country where that income is captured under a separate corporate tax regime. Without controlling for these structural differences, the U.S. income tax share can appear inflated compared to nations with different business reporting standards.
Official Responses and Expert Consensus
The release of this data has sparked renewed discussion among economists and policy analysts. Proponents of tax reform often point to the "Laffer Curve" effect, noting that while the U.S. system is already highly progressive, there are diminishing returns to further increasing marginal tax rates.
Research from the Congressional Budget Office consistently supports the finding that the U.S. tax code is highly progressive. CBO data frequently shows that the highest-earning quintile of Americans pays a share of federal taxes that far exceeds their share of total income. Meanwhile, economists such as David Splinter and Gerald Auten have argued that when tax data is adjusted for the aforementioned pass-through business income and transfer payments, the narrative of "exploding inequality" driven by tax policy is significantly tempered.
Implications for Future Policy
For U.S. policymakers, the implications of this study are profound. As the country approaches future fiscal debates—ranging from the expiration of tax provisions to potential overhauls of the corporate and individual codes—the "international context" must be prioritized.
- The Risk of Over-Reliance on Marginal Rates: The study suggests that the U.S. has little "room to move" in terms of further increasing the progressivity of its tax structure without triggering the negative economic externalities associated with high marginal rates, such as capital flight or decreased investment.
- Focusing on Efficiency: If the U.S. already possesses the most progressive tax code in the developed world, future reform should perhaps focus on economic growth, broadening the base, and improving the efficiency of tax administration rather than simply hiking top-end rates.
- Global Competitiveness: The reliance on income tax over consumption tax is a unique American feature. Any move toward a national consumption tax (or VAT) to address revenue gaps would fundamentally alter the U.S. standing in these progressivity metrics, potentially making the code appear "less progressive" by the very standards used to measure it.
Conclusion: A Clearer Picture
The Fraser Institute’s findings provide a much-needed empirical anchor in an often-heated debate. By demonstrating that the United States already maintains a highly progressive tax structure—often more so than the social democracies of Europe—the study forces a reevaluation of the political rhetoric surrounding American taxation.
While the index acknowledges that no comparative model is perfect, the evidence remains consistent: the American tax system is not the regressive outlier that critics often claim. As policymakers look toward the future, they must weigh the potential benefits of further redistribution against the economic realities of a system that already places the heaviest burden on the top of the income distribution. The data suggests that the U.S. has already achieved a high level of structural progressivity; the question for the future is not how to make the system more progressive, but how to ensure that the current system remains both fair and conducive to long-term economic prosperity.
