Research Interests

Corporate innovation, q-theory of investment, behavioral finance

Working Papers

Using Patent Capital to Estimate Tobin's q

I construct a new proxy for Tobin's q that incorporates the replacement cost of patent capital. This proxy, PI (physical plus intangible) q, explains up to 64% more variation in investment than other proxies for q. Furthermore, investment is more sensitive to PI q than to other proxies for q. Although investment is predicted more accurately by, and is more sensitive to, PI q, controlling for PI q leads to relatively higher, not lower, cash flow coefficients. All results are stronger in subsamples with more patent capital. Overall, using PI q strengthens the historically weak investment-q relation.

Small Innovators: No Risk, No Return (with Noah Stoffman and M. Deniz Yavuz)

We find that small innovators (i.e., small, innovative firms) earn higher returns than small non-innovators for up to five years. We find no such innovative premium among large firms. A battery of tests shows that our results are explained by risk, not investor underreaction. Small innovators are especially risky because they focus more on risky product innovation and rely more on organization capital that amplifies their systematic risk. In addition, small innovators contribute significantly to the size premium. Overall, small innovators have a higher cost of equity, which potentially explains why they rely heavily on internal capital.

Works in Progress

Price-Path Convexity, Extrapolation, and Short-Horizon Return Predictability (with Zhi Da and Huseyin Gulen)

We document a strong relation between intra-month stock price paths and subsequent one-month returns. Specifically, stocks whose prices increase at an increasing rate (i.e., stocks with convex price paths) subsequently underperform stocks whose prices decrease at an increasing rate. This effect ranges from 1.34% to 1.53% per month and is not explained by either the sign of the return over the sorting month or commonly-used predictors of short-term returns. We find similar results in non-US G7 countries and at the aggregate level in the US. We argue that the negative relation between price-path convexity and subsequent one-month returns is consistent with investor over-extrapolation of recent price changes.