Stocks are a bad short-run inflation hedge and the best long-run one
The claim
Equity returns are negatively correlated with inflation over horizons of a year to a few years, and positively related to it over multi-decade horizons, so equities protect purchasing power eventually rather than immediately.
Why we rate it moderate
The short-horizon negative relationship is one of the most replicated results in empirical finance. The long-horizon reversal is harder to establish because overlapping long windows leave few independent observations.
Fama and Schwert documented the awkward result: over short horizons, common stock returns are negatively related to both expected and unexpected inflation. Equities are claims on real assets, so the theory says they should keep up — but in the data, inflation surprises are bad for stocks in the year they arrive. Rising inflation raises discount rates and usually arrives alongside slowing growth and tightening policy, and those effects dominate.
Over long horizons the relationship inverts, because earnings and dividends are nominal quantities that rise with the price level. The bundled history on this site shows it plainly: across the full record, US equities compounded a large real gain despite passing through the 1940s and the 1970s. The 1970s are the honest counter-example — real equity returns over 1966 to 1982 were negative even though nominal returns were roughly flat, and it took sixteen years to resolve.
Bonds are the clearer casualty. A nominal bond promises fixed cash flows, so unexpected inflation transfers wealth from the lender to the borrower directly, and duration determines how much. 2022 was the demonstration: inflation surprised upward, long duration repriced, and stocks and bonds fell together — the failure mode a 60/40 portfolio is not supposed to have, and one that follows straightforwardly from both being priced off the same discount rate.
The instruments that hedge inflation directly are the ones indexed to it. TIPS pay a real coupon on a principal that tracks CPI, and Series I savings bonds do something similar for small amounts with a purchase limit. Neither is a growth asset; both are the right tool if the specific risk you are hedging is a fixed nominal liability meeting an unexpected price level.
The planning version: hold equities for the multi-decade real return, do not expect them to protect you in the year inflation arrives, and if you have near-term real spending to defend — the first years of retirement, most obviously — defend it with something actually indexed rather than with an asset that gets there eventually.
Where this breaks down
- The mechanism behind the short-run negative correlation is still argued over: money illusion in discount rates, and the correlation between inflation shocks and growth shocks, both have support.
- Long-horizon evidence uses overlapping windows, so the effective sample is far smaller than the number of observations suggests.
- The relationship is regime-dependent. The stock-bond correlation itself flipped sign between the 1970s and the 2000s, and flipped back in 2022.
- Hyperinflation and sustained double-digit inflation are outside the range of most of this evidence, and equity behaviour in those regimes is documented mainly outside the US.
Sources
Follow these rather than taking our word for the summary.
Eugene F. Fama and G. William Schwert (1977). Asset returns and inflation
Journal of Financial Economics, 5(2), 115-146
Finding: Common stock returns were negatively related to both the expected and the unexpected components of inflation over short horizons.
John Y. Campbell and Luis M. Viceira (1999). Consumption and Portfolio Decisions when Expected Returns are Time Varying
The Quarterly Journal of Economics, 114(2), 433-495
Finding: Optimal portfolio choice depends on the investor's horizon when expected returns vary over time, so short-horizon and long-horizon risk are not the same quantity.