R&D investments and idiosyncratic volatility: evidence from a quasi-natural experiment

Abstract

ABSTRACT An intriguing phenomenon in the U.S. stock market is that the level of average stock return volatility has increased considerably since the 1960s. We argue that corporate R&D investments provide an explanation for this phenomenon due to the uncertainties of R&D investment payouts and the information asymmetry between firms and investors. We employ a quasi-natural experiment, namely, the changes in state-level R&D tax credits in the U.S. to investigate the effect of R&D investments on idiosyncratic volatility. The results of baseline regressions show that a one-standard-deviation increase in R&D tax credits (user cost of R&D capital) is associated with a 0.013 (0.049) standard-deviation increase (reduction) in idiosyncratic volatility. This finding provides an explanation for the increasing trend in the average stock return volatility over the recent decades.