NBER Working Papers by Jin Ginger Wu

We construct accounting-based costs of equity for dollar neutral long-short trading strategies formed on a comprehensive list of anomaly variables. These variables include book-to-market, size, composite issuance, net stock issues, abnormal investment, asset growth, investment-to-assets, accruals, earnings surprises, failure probability, return on assets, and short-term prior returns. Our findings are striking. Except for the value premium, cost of equity estimates differ dramatically from average realized returns. If accounting-based costs of equity are reasonable proxies for expected returns, the evidence implies that returns of most anomalies are unexpected, and that mispricing, not risk, is the main driving force of capital markets anomalies.

Interpreting accruals as working capital investment, we hypothesize that firms rationally adjust their investment to respond to discount rate changes. Consistent with the optimal investment hypothesis, we document that (i) the predictive power of accruals for future stock returns increases with the covariations of accruals with past and current stock returns, and (ii) adding investment- based factors into standard factor regressions substantially reduces the magnitude of the accrual anomaly. High accrual firms also have similar corporate governance and entrenchment indexes as low accrual firms. This evidence suggests that the accrual anomaly is more likely to be driven by optimal investment than by investor overreaction to excessive growth or over-investment.