[kyralis]

You're missing that the company has the same information from a pool of other existing employees or candidates, and you do not. The information is not 50%, because you're in the dark about the state of the market - you're highly likely to be leaving money on the table. It's similar to why insider trading is illegal: one party is playing with non-public information.

[timr]

No, I'm not missing that. First, you're not "dark" -- it's pretty easy to get a sense of what the market will pay. There are tons of resources. The average company is not getting better information than you are about regional salaries, which is all you really care about. If nothing else, you can find this information by just going out and negotiating a few times.

Second, the big companies will (sometimes) pay for salary data, but this information falls in the "what the company is willing to pay" bucket. Again, that's 50% of the information to make a deal, and you don't need to know it. From your perspective, it doesn't matter if they got their salary band by consulting a survey or a magic 8 ball. Maybe it affects the level of faux outrage they show when you ask for more, but then you're just back to negotiation.

Said differently, if you know you're worth $X, and the company believes that the statistical average human cog in Barnsville, Nebrahoma is worth $Y, what do you care why they believe that? Your job is to find the highest number between $X and $Y that they will accept, based on your unique value. Their job is to convince you to join, and maybe get that number closer to $Y. Their justification for $Y is not your concern.