A nominal-minus-inflation-linked yield spread contains more than expected inflation. Federal Reserve research separates risk compensation and TIPS liquidity effects.
What the primary record establishes
In a research note published on 21 May 2019, Federal Reserve economists decomposed TIPS inflation compensation into expected inflation, an inflation risk premium and a subtractive TIPS liquidity premium. The note explains a modelling framework; it is not a current FOMC forecast. Federal Reserve economists — Tips from TIPS, 21 May 2019 ↗
The liquidity component reflects the difference between observed TIPS yields and the model’s underlying real yield. Consequently, a change in the nominal–TIPS spread does not uniquely identify a change in inflation expectations. Different components can move together or offset one another. Federal Reserve economists — Tips from TIPS, 21 May 2019 ↗
What the distinction changes
Suppose, purely for illustration, a nominal yield is 4.0% and a comparable TIPS yield is 1.8%. The arithmetic spread is 2.2 percentage points. Calling that number a precise forecast of future CPI would require additional assumptions about premiums and measurement.
This distinction matters to FX analysis because a currency narrative often links changing bond yields to monetary expectations. A wider spread can be consistent with several explanations. Its direction alone cannot establish whether investors revised inflation, risk compensation or relative liquidity.
What to check before drawing a conclusion
Compare matching maturities and compatible yield constructions. A par yield, a zero-coupon estimate and a forward rate are different objects. The observation timestamp also matters when comparing a daily bond measure with an intraday currency move.
Use surveys and documented model estimates as separate evidence, retaining their assumptions and uncertainty. Report the observed spread as inflation compensation unless a defensible decomposition supports a narrower description. The illustrative figures here are not market observations.