Cumulative Prospect Theory, Employee Exercise Behaviour and Stock Options Cost Assessment

In this paper, we introduce a new framework for the analysis of employee stock options exercise decisions. We develop a distorted lattice model where the exercise decision obeys a policy that maximizes the expected value of the exercise outcomes under the Cumulative Prospect Theory. Using a large US dataset of exercise transactions, we show that our framework broadly outperforms the Expected Utility Theory framework in explaining empirical exercise decisions. Interestingly, our empirical estimates of probability weighting are consistent with those from the experimental literature. We argue that this analysis provides a unifying stream for thinking about issues related to the exercise and the valuation of stock options.