The 50-year affordability race

No single public dataset covers 50 years of incomes and home prices at this grain, so this app splices measured series and labels every estimated segment:

• Measured: state median household income 1984-2024 (Census CPS H-8); the FHFA house price index 1975-2024 (the shape of every price path); listing $/sqft 2017-2024 (Realtor.com); CPI-U (BLS); 30-year mortgage rates 1971-2024 (Freddie Mac PMMS).
• Price levels: each state's FHFA index is rebased so its 2024 value equals its 2024 average Zillow ZHVI. Earlier dollar levels inherit the measured index shape.
• State income 1975-1983 (estimated): each state's position relative to the US median is interpolated between its 1969 and 1979 decennial census anchors and its 1984 CPS value, then applied to the measured US median for each year.
• Metro income (measured 2023+, estimated before): ACS 1-year medians anchor each metro; earlier years scale the state median by the metro's income premium over its state, taken from BEA county personal income aggregated to the metro (measured annually back to 1969). Holding the 2023 anchor and predicting the measured 2024 value lands within 3.4% for the median metro (worst 8%).
• Metro definitions: current CBSA boundaries throughout; the largest metros use their FHFA metro-division index (San Francisco means the SF-San Mateo-Redwood City division, New York means NY-Jersey City-White Plains). Bubbles appear when a metro's FHFA index begins.
• $/sqft before 2017 (estimated): backcast from the geography's 2017 value along its FHFA index.
• Average toggles (estimated): state medians scaled by the national mean-to-median ratio for that year (income: Census H-6, measured 1975-2024; price: Census new-home average vs median, 2023 ratio held for 2024).
• Mortgage payment (derived): monthly principal and interest on the median home: 20% down, 30-year fixed, at that year's average 30-year rate from Freddie Mac's weekly PMMS survey (1971+). No taxes, insurance, or PMI. The payment is a nominal cash flow for its year; the real toggle deflates it like every other dollar figure. Guide lines switch to payment-burden rays, including the classic 28%-of-income lender rule.
• Inflation toggle: CPI-U, expressed in 2025 dollars. Price-to-income ratios are unaffected by it. Bubble area always uses 2025-dollar $/sqft so sizes stay comparable across the toggle.