DP12926 Estimating Latent Asset-Pricing Factors

Author(s): Martin Lettau, Markus Pelger
Publication Date: May 2018
Date Revised: June 2018
Keyword(s): Anomalies, Cross Section of Returns, expected returns, high-dimensional data, Latent Factors, PCA, Weak Factors
JEL(s): C14, C38, C52, C58, G12
Programme Areas: Financial Economics
Link to this Page: www.cepr.org/active/publications/discussion_papers/dp.php?dpno=12926

We develop an estimator for latent factors in a large-dimensional panel of financial data that can explain expected excess returns. Statistical factor analysis based on Principal Component Analysis (PCA) has problems identifying factors with a small variance that are important for asset pricing. We generalize PCA with a penalty term accounting for the pricing error in expected returns. Our estimator searches for factors that can explain both the expected return and covariance structure. We derive the statistical properties of the new estimator and show that our estimator can find asset-pricing factors, which cannot be detected with PCA, even if a large amount of data is available. Applying the approach to portfolio data we find factors with Sharpe-ratios more than twice as large as those based on conventional PCA and with significantly smaller pricing errors.