We present a pricing kernel that summarizes well the main features of the dynamics of interest rates and risk in postwar U.S. data and use it to uncover how the pricing kernel has moved with the short rate in this data. Our findings imply that standard monetary models miss an essential link between the central bank instrument and the economic activity that monetary policy is intended to affect and thus we call for a new approach to monetary policy analysis. We sketch a new approach using an economic model based on our pricing kernel. The model incorporates the key relationships between policy and risk movements in an unconventional way: the central bank's policy changes are viewed as primarily intended to compensate for exogenous business cycle fluctuations in risk which threaten to push inflation off target. This model, while an improvement on standard models, is considered just a starting point for their revision. It leads to critical questions that researchers need to answer as they continue to revise their approach to monetary policy analysis. In this paper we use data on the dynamics of interest rates and risk to uncover how the pricing kernel has moved with the short rate in postwar U.S. data. Our two main findings are that• Most (over 90%) of the movements in the short rate correspond to random walk movements in the conditional mean of the pricing kernel. We refer to these movements as the secular movements in the short rate.• The remaining movements in the short rate, which we refer to as the business cycle movements in the short rate correspond to movements in the conditional variance of the pricing kernel associated with changes in risk.Standard models used for monetary policy analysis are inconsistent, by construction, with these regularities and, hence, do not capture how the pricing kernel moves with the short rate. We argue that this inconsistency is a serious problem if we want to use these models to understand monetary policy and the macroeconomy. We argue that a new approach to analyzing monetary policy is needed.Here we sketch a new approach to analyzing monetary policy. To do so we build an economic model consistent with the comovements of interest rates and risk found in U.S.data. Using this model we interpret postwar monetary policy as follows.• Secular movements of the short rate arise as a result of random walk movements in the Fed's inflation target.