BCAM, October 09th 2026, 13:00 - 13:30
The mathematical explanation of democracy's failure.
Claudia Peña (BCAM).
Democracy is built on a deceptively simple idea: individuals have different preferences, and it should be possible to aggregate them and determine what the majority of the group wants. Can this be actually done consistenly?
In this talk we will explore the mathematical difficulties hidden behind this innocent question.We will explore Arrow's Impossibility Theorem (1951) and the mathematical obstructions it reveals: under apparently reasonable voting rules, there is no voting system can transform individual preferences into a collective ranking without running into surprising paradoxes.