Asset pricing models are most commonly built to address opuzzlespin either equity or bond markets. A question that seems worth asking is whether this habitual separation does not make one loose sight of much of the commonality in the behavior of asset pricing anomalies across markets. A commonality which by itself would not seem surprising, if one accepts a relation between macroeconomic aggregates and risk premia in asset markets to exist.
In the empirical asset pricing literature, the integration of bond and equity markets has long been an extensively studied topic. Keim and Stambaugh (1986), for example, construct bond and stock market variables which they find capable of jointly predicting risk premia of common stocks, as well as, corporate and government bonds. Cochrane and Piazzesi (2005) find a single return forecasting factor for one to five year maturity bonds, which turns out to be counter cyclical and to also forecast stock returns. Fama and French (1989) find a term premium with a clear business cycle pattern, showing that the returns on stocks and bonds move together. Moreover, they find that dividend yields, as well as, default spreads forecast returns on both stocks and bonds to be high, when business conditions are weak and low, when they are strong.