We analyze a large data set of stock option exercises for a large data set of almost 200,000 option packages for more than 16,000 US top executives and analyze their motivations for the early exercise of their stock options. We estimate a hazard model to identify the main variables that influence executives´ timing decisions and find that behavioral factors (e.g. , trends in past stock prices), institutional factors (vesting dates, grant dates, blackout periods) an inside information strongly influence the timing of stock option exercises. By contrast, we find little support for the influence of variables proposed by utility-based models
