Covariances between aggregate stock returns and changes in bond yields change sign over time. Existing theories emphasize either time-varying properties of expected inflation or time-varying properties of real yields. Using revisions in survey forecasts as proxies for macroeconomic news, neither approach succeeds empirically. Inflation-centric models require much more news about expected future inflation than we observe from surveys. Real-centric models posit signs of covariances among macroeconomic news, changes in yields, and stock returns that do not match those in the data. In a nutshell, macroeconomic news appears to drive a substantial part of stock–bond comovement, but not in ways consistent with our theories.

ABSTRACT 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.