Inflation and Investment Returns in the US — Real Returns After Tax

## Historical US inflation and returns US CPI inflation averaged ~3% over the 20th century, but 2021–2023 saw peaks above 8%. For planning purposes, 2.5–3% is a reasonable long-term assumption. ## Real returns of major US asset classes (1928–2023) - S&P 500: ~10% nominal, ~7% real - 10-year Treasury bonds: ~5% nominal, ~2% real - T-bills: ~3.4% nominal, ~0.4% real (barely beats inflation) - Gold: ~4.2% nominal, ~1.2% real Equity has been the only reliable inflation-beating asset over long periods. ## TIPS — Inflation-Protected Securities Treasury Inflation-Protected Securities (TIPS) adjust principal with CPI. They guarantee a real return above inflation — useful for inflation-sensitive goals. I-bonds offer a similar guarantee for up to $10,000/year and were highly popular during the 2022 inflation spike. ## The 4% rule and inflation The famous 4% retirement withdrawal rule already accounts for inflation — it was derived from 30-year periods including high-inflation scenarios. But if inflation runs consistently above 4–5% during retirement, the 4% rule may need to be revised downward.