Arrow's Impossibility Theorem

Above all, everyone wants voting to be fair. What does fair mean and how can we measure it? Kenneth Arrow posited a simple set of conditions that one would certainly desire in a voting system. For example, unanimity - if everyone picks candidate A, then A should win!

Yet surprisingly, under a few basic assumptions, this theorem demonstrates that no voting system exists which can satisfy all the criteria.

This episode is a discussion about the structure of the proof and some of its implications.

**Works Mentioned**

[A Difficulty in the Concept of Social Welfare by Kenneth J. Arrow](https://www.stat.uchicago.edu/~lekheng/meetings/mathofranking/ref/arrow.pdf)

[Three Brief Proofs of Arrows Impossibility Theorem by John Geanakoplos](http://dido.econ.yale.edu/~gean/art/p1116.pdf)

**Thank you to our sponsors!**

**Better Help** is much more affordable than traditional offline counseling, and financial aid is available! Get started in less than 24 hours. Data Skeptic listeners get 10% off your first month when you visit: [betterhelp.com/dataskeptic](https://betterhelp.com/dataskeptic)

Let **Springboard School of Data** jumpstart your data career! With 100% online and remote schooling, supported by a vast network of professional mentors with a tuition-back guarantee, you can't go wrong. Up to twenty $500 scholarships will be awarded to Data Skeptic listeners. Check them out at [springboard.com/dataskeptic](https://springboard.com/dataskeptic) and enroll using code: DATASK

Guest

John Geanakoplos