It also takes away from them the riposte of "you're full of shit" or "that number is crazy" because it comes from the biggest Human Resources dept on the planet. It's maybe my favorite interview tactic I've come up with, both for negotiation value and from keeping people from wasting my time. "You're not even going to pay more than the government, even though you have shit benefits by comparison? Adios. Don't call yourself competitive."

In strategic terms it also "inverts the information asymmetry" they like to exploit; "We're a company and you're just one person with an idea of how much you should make" becomes "You're just a little company, this is what the largest employer anywhere thinks I'm worth".