>So employees with limited power and authority over their little domain, are going to act in their own interests by as you say hiring people like themselves, by

>So employees with limited power and authority over their little domain, are going to act in their own interests by as you say hiring people like themselves, by creating a culture that matches their values and keeps outsiders at bay, and by ousting anything that threatens the status quo. The thing you are missing is that while I may benefit when /other people/ discriminate in favor of my group, as an individual? I actually lose out if I discriminate based on irrelevant factors. (Now, if there was some kind of enforcement of this clan altruism; if I stopped getting the in-group benefits because I refused to place the interests of the group before my own interests, then it'd be different. But I haven't seen any cases, at least in my career, where that sort of defection is punished.) Now, there are all sorts of emotional/cultural reasons to discriminate against outsiders, if you have a strong group identity, but it's certainly not in your financial best interest. Trade unions don't have a significantly better history with discrimination than management does. This problem goes far beyond monetary self-interest.