The exercise and valuation of executive stock options
利用40家公司的期权行使数据，发现随机外生行使和没收的简单模型在预测实际行使时间和收益方面，与复杂的效用最大化模型效果相当，因此对高管期权估值更实用。
In theory, hedging restrictions faced by managers make executive stock options more difficult to value than ordinary options, because they imply that exercise policies of managers depend on their preferences and endowments. Using data on option exercises from 40 firms, this paper shows that a simple extension of the ordinary American option model which introduces random, exogenous exercise and forfeiture predicts actual exercise times and payoffs just as well as an elaborate utility-maximizing model that explicitly accounts for the nontransferability of options. The simpler model could therefore be more useful than the preference-based model for valuing executive options in practice.