Your meal is free if you don’t get a receipt. Please see a manager.
The principle (for ex. Burger King) employs an agent (the cashier) who has an incentive to do a lot of things that are not necessarily in the best interest of the firm (i.e. steal). Burger King can either spend a lot of time and money monitoring its employees for theft, or it can provide an incentive for you to do it for them. That little sign by the cash register is an ingenious management tool.
- excerpt from Naked Economics
