This paper shows that supply shock uncertainty interacts with the monetary policy rule to drive bond risks in a New Keynesian asset pricing model. In my model, positive nominal bond-stock betas emerge as the result of volatile supply shocks but only if the monetary policy rule features a high inflation weight. Habit formation preferences generate endogenously time-varying risk premia, explaining the volatility and predictability of bond and stock excess returns in the data, and implying that bond-stock betas price the expected equilibrium mix of shocks rather than realized shocks. The model explains the change from positive nominal and real bond-stock betas in the 1980s to negative nominal and real bond-stock betas in the 2000s with a shift from dominant supply shocks and an inflation-focused monetary policy rule, to demand shocks in the 2000s. Post-pandemic nominal and real bond-stock betas are explained with dominant supply shocks and a late increase in the monetary policy inflation coefficient.

We show that endogenous variation in risk aversion over the business cycle can jointly explain financial market responses to high-frequency monetary policy shocks with standard asset pricing moments. We newly integrate a work-horse New Keynesian model with countercyclical risk aversion via habit formation preferences. In the model, a surprise increase in the policy rate lowers consumption relative to habit, raising risk aversion. Endogenously time-varying risk aversion in the model is crucial to explain the large fall in the stock market, the cross-section of industry returns, and the increase in long-term bond yields in response to a surprise policy rate increase.

We estimate perceptions about the Federal Reserve’s monetary policy rule from panel data on professional forecasts of interest rates and macroeconomic conditions. The perceived dependence of the federal funds rate on economic conditions varies substantially over time, in particular over the monetary policy cycle. Forecasters update their perceptions about the Fed’s policy rule in response to monetary policy actions, measured by high-frequency interest rate surprises, suggesting that they have imperfect information about the rule. Monetary policy perceptions matter for monetary transmission, as they affect the sensitivity of interest rates to macroeconomic news, term premia in long-term bonds, and the response of the stock market to monetary policy surprises. A simple learning model with forecaster heterogeneity and incomplete information about the policy rule motivates and explains our empirical findings.

We document that governments whose local currency debt provides them with greater hedging benefits actually borrow more in foreign currency. We introduce two features into a government's debt portfolio choice problem to explain this finding: risk‐averse lenders and lack of monetary policy commitment. A government without commitment chooses excessively countercyclical inflation ex post, which leads risk‐averse lenders to require a risk premium ex ante. This makes local currency debt too expensive from the government's perspective and thereby discourages the government from borrowing in its own currency.