Revisions in successive Greenbook forecasts of quarterly real GDP growth proxy for news of current and expected future economic growth. In the sample 1975 through 2015, news of future growth is slightly negatively related to contemporaneous changes in Treasury bond yields, while news of current growth is strongly positively related to changes in these yields. Both results are difficult to reconcile with a representative agent's bondholding first‐order condition. A continuous‐time dynamic model of output attributes almost all of the covariation with yields to martingale innovations in log output and a minimal amount to innovations in the conditional drift of log output.

Shocks to nominal bond yields consist of news about expected future inflation, expected future real short rates, and expected excess returns—all over the bond's life. I estimate the magnitude of the first component for short‐ and long‐maturity Treasury bonds. At a quarterly frequency, variances of news about expected inflation account for between 10% to 20% of variances of yield shocks. Standard dynamic models with long‐run risk imply variance ratios close to 1. Habit formation models fare somewhat better. The magnitudes of shocks to real rates and expected excess returns cannot be determined reliably.

The conditional covariance between aggregate stock returns and aggregate consumption growth varies substantially over time. When stock market wealth is high relative to consumption, both the conditional covariance and correlation are high. This pattern is consistent with the “composition effect,” where agents' consumption growth is more closely tied to stock returns when stock wealth is a larger share of total wealth. This variation can be used to test asset‐pricing models in which the price of consumption risk varies. After accounting for variations in this price, the relation between expected excess stock returns and the conditional covariance is negative.

The standard class of affine models produces poor forecasts of future Treasury yields. Better forecasts are generated by assuming that yields follow random walks. The failure of these models is driven by one of their key features: Compensation for risk is a multiple of the variance of the risk. Thus risk compensation cannot vary independently of interest rate volatility. I also describe a broader class of models. These aessentially affine‐ models retain the tractability of standard models, but allow compensation for interest rate risk to vary independently of interest rate volatility. This additional flexibility proves useful in forecasting future yields.

Because the option to call a corporate bond should rise in value when bond yields fall, the relation between noncallable Treasury yields and spreads of corporate bond yields over Treasury yields should depend on the callability of the corporate bond. I confirm this hypothesis for investment-grade corporate bonds. Although yield spreads on both callable and noncallable corporate bonds fall when Treasury yields rise, this relation is much stronger for callable bonds. This result has important implications for interpreting the behavior of yields on commonly used corporate bond indexes, which are composed primarily of callable bonds.

Because the option to call a corporate bond should rise in value when bond yields fall, the relation between noncallable Treasury yields and spreads of corporate bond yields over Treasury yields should depend on the callability of the corporate bond. I confirm this hypothesis for investment‐grade corporate bonds. Although yield spreads on both callable and noncallable corporate bonds fall when Treasury yields rise, this relation is much stronger for callable bonds. This result has important implications for interpreting the behavior of yields on commonly used corporate bond indexes, which are composed primarily of callable bonds.

I document a dramatic increase in the importance of two types of variation in Treasury bill yields beginning in the early 1980s. The first is idiosyncratic variation in individual short‐maturity (less than three months) bill yields. The second is a common component in Treasury bill yields that is not shared by yields on other instruments, such as short‐maturity privately‐issued instruments or longer‐maturity Treasury notes and bonds. Some evidence suggests the first type reflects increased market segmentation. These results have important implications for the calibration and testing of no‐arbitrage term structure models and interpreting tests of the expectations hypothesis.

I document a dramatic increase in the importance of two types of variation in Treasury bill yields beginning in the early 1980s. The first is idiosyncratic variation in individual short-maturity (less than three months) bill yields. The second is a common component in Treasury bill yields that is not shared by yields on other instruments, such as short-maturity privately-issued instruments or longer-maturity Treasury notes and bonds. Some evidence suggests the first type reflects increased market segmentation. These results have important implications for the calibration and testing of no-arbitrage term structure models and interpreting tests of the expectations hypothesis.

The author documents a dramatic increase in the importance of two types of variation in Treasury bill yields beginning in the early 1980s. The first is idiosyncratic variation in individual short-maturity (less than three months) bill yields. The second is a common component in Treasury bill yields that is not shared by yields on other instruments, such as short-maturity privately issued instruments or longer-maturity Treasury notes and bonds. Some evidence suggests the first type reflects increased market segmentation. These results have important implications for the calibration and testing of no-arbitrage term structure models and interpreting tests of the expectations hypothesis.