American Affordability Graph (1945–2026)

Sourced from U.S. Census Bureau Historical Income Tables. For 1991–2026, educational cohorts utilize Table P-18 / PINC-03. For 1945–1990, income levels are reconstructed using Census Series P-60 reports and historical decennial occupational benchmarks. Household income assumes dual comparable earners.

Combines historical FICA payroll taxes (rising from 1.0% in 1945 to 7.65% by 1990) with effective federal and state income tax rate models. Historical rates are calibrated against the historical IRS tax brackets for corresponding annual income levels.

Calculates standard Principal & Interest (P&I) payments on a 30-year fixed mortgage with a 20% down payment. Base home prices utilize FRED MSPUS (national median sale price) scaled by local indices. Interest rates reflect FRED MORTGAGE30US historical averages. Includes local property tax estimates.

Computes 48-month auto loan payments for two vehicles (10% down) using historical financing rates (FRED TERMCBAUTO48NS) and new car prices (FRED CUUR0000SETA01) scaled to average transaction figures. Fuel costs calculate 2,000 monthly miles utilizing era-accurate average MPG and gasoline rates. Insurance scales by the CPI index.

Models essential expenditures (food, utilities, clothing, healthcare) from the BLS Consumer Expenditure Survey (CEX). Baselines are adjusted historically using BLS CPI sub-indices (Food, Medical Care, Apparel, Energy) and adjusted for household dependent scale.

Allocates a flat 4% of gross monthly income as standard budget savings for travel and leisure, scaled relative to the demographic's annual earnings capacity.