Estimation and Evaluation of Conditional Asset Pricing Models

We find that several recently proposed consumption-based models of stock returns, when evaluated using an optimal set of managed portfolios and the associated model-implied conditional moment restrictions, fail to capture key features of risk premiums in equity markets. To arrive at these conclusions, we construct an optimal GMM estimator for models in which the stochastic discount factor (SDF) is a conditionally affine function of a set of priced risk factors. Further, for the (often relevant) case where a researcher is proposing a generalized SDF relative to some null model, we show that there is an optimal choice of managed portfolios to use in testing the null against the proposed alternative.