10% of total number of full interviews that needed to be conducted. At most publicly listed companies, firing can't be done without accumulation of enough evide

10% of total number of full interviews that needed to be conducted. At most publicly listed companies, firing can't be done without accumulation of enough evidence (what HR usually refers to as "paper trail"). This is true even when employment was "at will" mainly because of legal liability (for example, fired employee can claim that he was a victim of XYZ) and bad PR it can generate. I think Facebook is (or was) probably rare exception in aggressive firing and not sure how they managed it. Most companies also require annual review to be in place before firing occurs. Typically hiring manager would avoid firing within first year because that usually looks very bad on them. Most true negatives don't get fired until hiring manager changes or years pass by. At startups things are obviously different. Resources are scarce and true negative probably won't survive beyond 6 month or in worse case beyond a year. But still that's a significant period to cause enough of hemorrhaging for a true negative.