How accurate is this process when it comes to determining average wages? A lot of companies keep those matters somewhat confidential. In fact, it is a firing offense in some companies to discuss salaries with anyone. The rationale seems to be some employees will take a morale hit if they find out other workers in similar positions are making more money, not to mention the competitive edge one business will have if it wants to hire away employees.
Are those policies common, or are enough companies open about how much they pay people that these studies are accurate?