Arrow's impossibility theorem

Can a perfect voting system exist?

Imagine you're voting for your favorite ice cream flavor. You prefer chocolate over vanilla, and vanilla over strawberry. But if strawberry is an option, chocolate might not win even though it's your top choice.

The idea is that adding more choices can mess up the outcome. Even if chocolate is your favorite, if strawberry is there, chocolate might not win. This is called Arrow's Impossibility Theorem.

Example

You prefer chocolate (C) over vanilla (V), and vanilla (V) over strawberry (S). But if strawberry (S) is an option, chocolate (C) might not win.

Remember this

Adding more choices can change the outcome, even if the original preferences stay the same.

Text adapted from Wikipedia, licensed under CC BY-SA 4.0.

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