Can Employee Stock Options Contribute to Less Risk‐Taking?
研究员工股票期权对风险承担的影响，发现期权价值对股价波动的敏感度（vega）与研发投资及回报呈倒U型关系，高vega反而导致风险规避。
ABSTRACT The executive compensation literature presumes that shareholders offer risk‐averse managers stock options to entice them to take on more risk, resulting in riskier investment decisions and thus a greater return on investment. However, recent empirical work challenges this assumption, and theoretical research even argues that high levels of option‐based compensation for generally under‐diversified managers may actually lead to greater risk aversion . We evaluate the incentive structure of employee stock options by examining the level of R&D investment and the return on that investment conditional on the portfolio “vega,” which captures the sensitivity of option value to stock price volatility. Our results suggest that both investment in R&D and the return on R&D, as measured by future earnings and patent awards, varies concavely with vega. That is, low to moderate levels of vega correspond to increasing investment in and returns on R&D, consistent with vega inducing more profitable investments, but marginal returns decline as vega increases. Collectively, these results, bolstered by several supplemental analyses, suggest that this surprising relation between vega and risky investment is driven by greater risk aversion at higher levels of vega. Overall, our results imply that employee stock options may not always align the incentives of managers and shareholders.