Information asymmetry
Etymology
"Asymmetry" is from Greek a- ("not") + symmetria ("proportion, balance"). Joined to "information," it names an imbalance in who-knows-what. The economist George Akerlof made it famous with "the market for lemons": if buyers can’t tell good used cars from bad, sellers of good ones can’t get a fair price.
noun · /in-fur-MAY-shun ay-SIM-uh-tree/
A situation where one side of a deal knows much more than the other.
What it names
Why used-car markets, insurance, and hiring are hard — the person with more knowledge can exploit the gap, and everyone else defends against it.
Example
The whole fee structure survived on information asymmetry — customers simply couldn’t tell what they were being charged for.
Related idea
Adverse selection and moral hazard are the two classic problems information asymmetry creates.