Real yield is the yield on a fixed-income investment expressed after accounting for inflation, so that the return is measured in purchasing-power rather than purely nominal terms. Conceptually, it is the yield that remains after removing the effect of inflation over the relevant horizon. In forward-looking market analysis, the relevant comparison is expected future inflation rather than the latest reported inflation rate. A common approximation is real yield ≈ nominal yield − expected inflation; more exactly, nominal rates, real rates and inflation are related multiplicatively rather than by simple subtraction.
Observed real yields are market prices, not inflation forecasts
In U.S. markets, real yields are commonly observed through Treasury Inflation-Protected Securities (TIPS). TIPS principal is adjusted with the Consumer Price Index, while the coupon rate is fixed and applied to the inflation-adjusted principal. Their market yields are therefore commonly interpreted as yields on inflation-linked Treasury cash flows in real terms. Real yields can be positive or negative. A negative real yield means that the market price implies a return below zero in purchasing-power terms before taxes, even though the security can still make positive nominal coupon payments and its principal can rise with inflation.
The difference between a nominal Treasury yield and a comparable TIPS real yield is commonly called breakeven inflation or inflation compensation. It is not a pure measure of expected inflation. Inflation-risk premiums, differences in liquidity between nominal Treasuries and TIPS, and other market effects can create a wedge between inflation compensation and investors' underlying inflation expectations. A change in real yields likewise does not identify a single economic cause: required real rates, expectations for monetary policy, term premiums and market conditions can all contribute.
The quoted number may not belong to any single bond
Researchers should also distinguish the yield of a particular TIPS from an official constant-maturity real-yield series. The U.S. Treasury's Real Constant Maturity Treasury rates are interpolated par real yields read from a fitted TIPS par real yield curve constructed from indicative secondary-market quotations. A quoted 10-year real constant-maturity rate can therefore exist even when no outstanding TIPS has exactly 10 years remaining to maturity. It is a constructed curve point, not necessarily the observed yield of a security at that precise maturity. This distinction matters when comparing datasets, backtesting rate relationships or interpreting small historical changes in “the” 10-year real yield.
Real yield is most useful as a measure of the market price of inflation-protected real interest-rate exposure. It is not, by itself, a forecast of economic growth, monetary policy or asset prices, and an investor's realized purchasing-power return can differ because of purchase and sale prices, holding period, taxes and differences between the inflation index used by the security and the investor's own cost of living.