How Do Tax Policies Explain Income Inequality? A State-by-State Breakdown of Tax Burdens vs. Income Levels

The relationship between taxation and income inequality is a central pillar of American fiscal policy, yet it varies dramatically from one state border to the next. While the federal government employs a progressive tax system to compress the after-tax income distribution, many state and local governments operate under “upside-down” systems. In these regressive frameworks, low- and middle-income families pay a significantly higher share of their total income in taxes than the wealthiest residents, often due to a heavy reliance on consumption taxes and the absence of graduated income tax brackets. This systemic disparity creates a fiscal environment where tax policy can either serve as a tool for social equity or a mechanism that widens the wealth gap.

Key Numbers

• 44 States: The number of states where tax systems are found to exacerbate income inequality [3].
• 60 Percent: The average increase in the effective tax rate faced by the lowest-income 20 percent of taxpayers compared to higher earners [1].
• 50 States: The scope of the distributional analysis conducted by the Institute on Taxation and Economic Policy (ITEP) [1].
• January 2024: The release date of the 7th edition of the ‘Who Pays?’ report [2].
• 100 Percent: The extent to which federal taxes are credited for reducing income inequality across all states, contrasting with state taxes which may widen the gap [4].

Explanation

Tax policies explain income inequality through the lens of progressivity and regressivity. A progressive tax system is one where the tax rate increases as the taxable amount increases, meaning high-income earners pay a larger percentage of their income. Conversely, a regressive tax system is one where the effective tax rate decreases as income rises. In many U.S. states, the reliance on sales taxes—which consume a larger portion of a low-income household’s budget—creates a regressive effect that disproportionately burdens those with the least ability to pay.

The “upside-down” nature of these systems is often driven by the lack of a graduated personal income tax. In states without such a tax, or those with flat taxes, the very wealthy can avoid paying taxes on a substantial portion of their income. While some states attempt to offset this regressivity through refundable credits, such as the Earned Income Tax Credit (EITC) or Child Tax Credits, these measures often only mitigate the burden at the very bottom of the income scale rather than restructuring the overall burden across the middle and upper classes.

Definition

In the context of fiscal analysis, distributional analysis refers to the study of how the burden of a tax system is spread across different income groups. The primary goal is to determine the effective tax rate—the actual percentage of total income paid in taxes after all credits, deductions, and exemptions are applied. When the effective rate for the bottom quintile is higher than that of the top quintile, the system is defined as regressive. When the rate increases alongside income, it is progressive.

State Comparison

State tax systems vary wildly based on their revenue mix. States that rely heavily on personal income taxes with multiple brackets tend to be more progressive. In contrast, states that have abolished income taxes entirely rely more heavily on sales and excise taxes, which are inherently regressive because lower-income individuals spend a higher percentage of their earnings on taxable goods.

Why It Matters

The structure of state taxes is not merely a matter of accounting; it has profound implications for economic mobility and poverty. When the lowest-income 20 percent of taxpayers face an effective tax rate nearly 60 percent higher than the wealthy, it reduces their disposable income for essential needs such as healthcare, education, and housing. This creates a cycle where the tax code itself hinders the ability of low-income families to accumulate wealth, thereby cementing existing income inequalities.

Factors Behind the Trend

Several structural factors contribute to the prevalence of regressive state tax systems:

• Absence of Graduated Taxes: Many states have moved toward flat taxes or have no income tax at all to attract high-net-worth individuals and businesses.
• Reliance on Consumption Taxes: Sales taxes are easier to collect and provide a steady revenue stream, but they hit low-income spenders hardest.
• Tax Expenditures: Loopholes and deductions often benefit those with complex portfolios (capital gains), while low-income earners have fewer opportunities for tax avoidance.
• Credit Dependence: Progressivity at the bottom is often an “add-on” via refundable credits rather than a structural feature of the tax brackets themselves [3].

Methodology

The analysis of tax burdens is typically conducted by calculating the effective state and local tax rate for various income quintiles. This involves:

1. Measuring all taxes paid by a household, including income, sales, property, and excise taxes.
2. Adjusting for tax credits (such as the EITC) that may result in a negative tax liability for the lowest earners.
3. Comparing these total payments against the total income of the household.
4. Aggregating this data across all 50 states and the District of Columbia to identify national trends [1].

Limitations of the Data

While distributional analyses provide critical insights, they are subject to certain limitations:

The data primarily focuses on state and local taxes. Because federal taxes are significantly more progressive than state taxes, the overall after-tax income distribution in all states is still reduced by federal intervention, even if state taxes widen the gap [4].

Additionally, these reports often rely on modeled data to estimate the tax burdens of the highest earners, as the most wealthy individuals frequently utilize sophisticated tax avoidance strategies that may not be fully captured in standard reporting.

Ranking Table: Tax Burden by Income Group

Based on the general findings of the 7th Edition of the “Who Pays?” report, the following table illustrates the typical distribution of tax burdens in regressive states.

Source & Data Date

The primary data for this analysis is sourced from the Institute on Taxation and Economic Policy (ITEP), specifically the 7th Edition of the “Who Pays?” report released in January 2024. Additional theoretical context regarding income compression is provided by the National Tax Journal (University of Chicago Press).