The Federal Reserve’s 2009 program to purchase $300 billion of US Treasury securities represented an unprecedented intervention in the Treasury market and provides a natural experiment with the potential to shed light on the price elasticities of Treasuries and theories of supply effects in the term structure. Using security-level data on Treasury prices and quantities during the course of this program, we document a ‘local supply’ effect in the yield curve—yields within a particular maturity sector responded more to changes in the amounts outstanding in that sector than to similar changes in other sectors. We find that this phenomenon was responsible for a persistent downward shift in yields averaging about 30 basis points over the course of the program (the “stock effect”). In addition, except at very long maturities, purchase operations caused an average decline in yields in the sector purchased of 3.5 basis points on the days when those operations occurred (the “flow effect”). The sensitivity of our results to security characteristics generally supports a view of segmentation or imperfect substitution within the Treasury market during this time.

We quantify the scarcity value of Treasury collateral by estimating the impact of security-specific demand and supply factors on the specific collateral repurchase agreement (repo) rates of all outstanding U.S. Treasury securities. We find a positive and significant scarcity premium for on- and off-the-run Treasuries that persists for approximately 3 months and is larger in magnitude for shorter-term securities. This scarcity effect seems to pass through to Treasury cash market prices, providing additional evidence for the scarcity channel of quantitative easing (QE). On the contrary, the Federal Reserve’s reverse repo operations could help reduce the scarcity premium by alleviating potential shortages of high-quality collateral.

To assess the importance of inflation risk for nominal Treasury yields, a novel quadratic term structure model with time-varying inflation risk is estimated using survey-based inflation uncertainty. The resulting yield decomposition captures very diverse macroeconomic dynamics of inflation and real risk premiums (large and positive during the 1980s but small and negative post-2008) and generates sensible high-frequency estimates of expected inflation and real short rates over a long sample. The explicit link between the model-implied factors and macro fundamentals reveals that short- but not long-run fluctuations are unspanned by yields, consistent with an interest rate policy unresponsive to transient inflation shocks.

Treasury Inflation-Protected Securities (TIPS) are frequently thought of as risk-free real bonds. Using no-arbitrage term structure models, we show that TIPS yields exceeded risk-free real yields by as much as 100 basis points when TIPS were first issued and up to 300 basis points during the 2007–2008 financial crisis. This spread predominantly reflects the poorer liquidity of TIPS relative to nominal Treasury securities. Other factors, including the indexation lag and the embedded deflation protection in TIPS, play a much smaller role. Ignoring this spread also significantly distorts the informational content of TIPS break-even inflation, a widely used proxy for expected inflation.

We price the risky component of specialness spreads—identified by their deviations from the expected auction cycle—within a dynamic term structure model estimated using daily prices of all outstanding Treasury securities and corresponding special collateral (SC) repo rates. This allows us to derive a time-varying SC risk premium that we quantitatively link to various price anomalies, such as the on-the-run premium. The SC risk premium explains about 80% of the on-the-run premium and a substantial share of other Treasury price anomalies, suggesting that unexpected fluctuations in the specialness spreads of recently issued nominal Treasury securities are a common risk factor.