I think that relates in part to how big the disparities are. If people are making mostly similar amounts of income, risk of discontent may not be as big an issu

I think that relates in part to how big the disparities are. If people are making mostly similar amounts of income, risk of discontent may not be as big an issue. For a large-scale example, Norway makes the annual income of the entire population public information, and yet the country isn't erupting in discontent. Of course other elements of culture (whether national or company culture) are involved as well.