[dputtick]

I'm not sure I agree that "the company has a huge incentive in firing him a day before he vests." First of all, the direct and indirect costs of hiring a replacement can be massive, and potentially larger than the value of the stock that isn't vested. An employee doesn't have to be "essential" in order to be extremely valuable, especially early on. Second, a company could make a habit of firing employees right before they vest, and even if they managed to completely mitigate the damage internally as soon as word got out about this practice they would suddenly find it impossible to hire quality talent.