Mispricing and Anomalies: An Exogenous Shock to Short Selling from JGTRRA

We investigate the causal impact of short-sale constraints on market anomalies by analyzing a comprehensive set of 182 anomalies. Our approach leverages a persistent, robust, and plausibly exogenous shock to short-selling supply caused by the dividend tax law change in the Job and Growth Tax Relief Reconciliation Act (JGTRRA) of 2003. Our findings reveal that anomalies decline after JGTRRA. However, this tax law change impedes arbitrageurs’ ability to correct mispricing, resulting in anomalies decaying less following dividend record months compared to other months post-JGTRRA. Furthermore, this effect is concentrated on overpriced stocks as opposed to underpriced stocks. Interestingly, while this shock significantly affects most types of anomalies, valuation anomalies remain unaffected.