Source Digest — Tax Foundation, Historical Federal Income Tax Rates and Brackets

Status (April 2026): Complete standard digest. Reference data source; one central cluster (the empirical shape of the U.S. income-tax ratchet) plus contextual notes on interpretation.

Why this digest: Friedberg's ratchet argument (Cluster 4 of the Modern Wisdom digest) claims taxes "started at 1% and only grow." The Tax Foundation's historical rate tables are the most widely cited public reference for U.S. federal individual income tax rates and brackets. This digest captures the data and its interpretive nuances so subsequent exchange rounds can distinguish what is actually true in the historical record from what is rhetorically asserted.

Source identification

Thematic cluster: the empirical shape of the U.S. income-tax ratchet

Core claims

• The modern federal income tax was established by the 16th Amendment (ratified 1913). It imposed 1% on net personal income above $3,000 (roughly $95,000 in 2026 dollars) with a 6% surtax above $500,000.
• Rates rose sharply during WWI (peaking at 77% on top incomes in 1918) and WWII (94% in 1944–1945).
• Top marginal rates remained above 70% from the late 1940s through 1981, then fell in two major waves:
  • 1981 (Reagan): top rate cut to 50%.
  • 1986 (Tax Reform Act): top rate cut to 28%.
  • Subsequent adjustments: 39.6% (1993), 35% (2003), 39.6% (2013), 37% (2017 TCJA, still in effect in 2026).
• The base of the income tax (who pays) expanded steadily. The 1943 Current Tax Payment Act introduced automatic employer withholding and transformed the income tax from a levy on a small top stratum into a universal mechanism.
• State income taxes are additive and vary widely. California's top marginal rate of 13.3% is the highest; seven states have no state income tax.

Representative statistic

In 1913, roughly 2% of U.S. households were subject to the federal income tax. By the end of WWII, that figure had risen above 60%. The brackets were also dramatically compressed: the 1913 bracket schedule had a 7-bracket structure ranging from 1% to 7%; by 1944, 24 brackets ranged from 23% to 94%.

Research context

Interpretive notes for the exchange

• Rates vs. base vs. effective rates. The Round 1 epistemic table in the Government Overreach exchange already distinguishes "the ratchet for the base" (steady) from "the ratchet for rates" (cyclical). This source is the strongest public reference for that distinction.
• Withholding as structural lock-in. The 1943 switch to automatic payroll withholding is arguably more consequential than any single rate change, because it removed the political friction of writing a tax check. This is a candidate example for Round 2's institutional-design analysis: what rules, once adopted, reshape the political economy of further rule changes?
• Brackets and inflation. Between 1913 and 1985, bracket thresholds were not indexed to inflation. Bracket creep pushed many middle-income households into higher statutory rates without explicit legislation. The 1985 indexation reform is an example of a ratchet mitigation.
• State-level variation matters. If the "ratchet" were a universal institutional dynamic, state-level tax histories should look similar. They do not. Seven states have sustained zero-income-tax regimes; several states have reduced income-tax rates materially in the past decade. See Tax Foundation, State Individual Income Tax Rates and Brackets for 2026.

Project 2028 mapping

• Exchange: Directly relevant to Government Overreach, Ownership as Transition, and the Ratchet Problem. Supplies the empirical scaffold for the "income-tax ratchet" question (Question 4 in Round 2 priorities).
• Problem Map: Domain 15 (Democratic process) and Domain 4 (Institutional capacity). Bracket creep and withholding are examples of quiet-default institutional design — the opposite of "legibility" called for in Principle 4.
• Protocol: Empirical input for the Historical Parallel Test Protocol.
• Use in Round 2: Pair with Higgs 1985 as the theoretical frame and with a heterodox counter-example (e.g., New Zealand 1984 or Argentina 2023–2025) to stress-test the ratchet.

Cross-references