While getting mathy, Dilbert gets his econ wrong. He gets right the comparative nature of humans with the comic's setup, but goes wrong with the "punchline". Humans compare what they will get with what they have, so percentage-based comparisons preserve this, while absolute quantity comparisons don't.
This comparison problem shows up all the time, as the same person would drive across town to save a dollar per gallon on gas, but not drive across town to save $100 on a $20,000 car. Their brain thinks ~33% versus 0.5%, and only drives cross-town for the larger, even though financially the opposite action should occur.
If we rewired all our motivation circuits to use financial sense instead of comparative sense, would C*O paychecks get smaller? Or is something else at work?