We describe the joint dynamics of bond yields and macroeconomic variables in a Vector Autoregression, where identifying restrictions are based on the absence of arbitrage. Using a term structure model with inflation and economic growth factors, together with latent variables, we investigate how macro variables affect bond prices and the dynamics of the yield curve. We find that the forecasting performance of a VAR improves when no-arbitrage restrictions are imposed and that models with macro factors forecast better than models with only unobservable factors.Variance decompositions show that macro factors explain up to 85% of the variation in bond yields. Macro factors primarily explain movements at the short end and middle of the yield curve while unobservable factors still account for most of the movement at the long end of the yield curve.

We study time variation in expected excess bond returns. We run regressions of one-year excess returns on initial forward rates. We find that a single factor, a single tent-shaped linear combination of forward rates, predicts excess returns on one- to five-year maturity bonds with R2 up to 0.44. The return-forecasting factor is countercyclical and forecasts stock returns. An important component of the return-forecasting factor is unrelated to the level, slope, and curvature movements described by most term structure models. We document that measurement errors do not affect our central results.

This paper studies time variation in expected excess bond returns. We run regressions of annual excess returns on forward rates. We find that a single factor predicts 1-year excess returns on 1-5 year maturity bonds with an R 2 up to 43%. The single factor is a tent-shaped linear function of forward rates. The return forecasting factor has a clear business cycle correlation: Expected returns are high in bad times, and low in good times, and the return-forecasting factor forecasts longrun output growth. The return-forecasting factor also forecasts stock returns, suggesting a common time-varying premium for real interest rate risk. The return forecasting factor is poorly related to level, slope, and curvature movements in bond yields. Therefore, it represents a source of yield curve movement not captured by most term structure models. Though the return-forecasting factor accounts for more than 99% of the time-variation in expected excess bond returns, we find additional, very small factors that forecast equally small differences between long term bond returns, and hence statistically reject a one-factor model for expected returns.