Hi everyone,
This week, Nico Aiello will be speaking on: “Why vote? The only reasonable voting system is a dictatorship” (abstract below). As always, pizza and soda will be provided. We’ll also be back in our usual room, LGRT1634 from 5:30-6:30
Abstract:
In honor of election season, we will discuss voting theory and Arrow’s Impossibility Theorem. It is not difficult to convince yourself that if we were to design a voting system, we would want the following two fairness criteria to be satisfied: 1) if every voter prefers X over Y, then society prefers X over Y and 2) if every voter’s preference between X and Y remains unchanged, then society’s preference between X and Y also remains unchanged. And yet, in his 1949 PhD thesis, Kenneth Arrow proved that if there are more than two choices in an election, the only rank-order voting system that satisfies both of the above conditions is a dictatorship. We will prove this somewhat troubling theorem and discuss what “fixes” can be made to our voting system to sidestep Arrow’s negative conclusion. This talk assumes no mathematical background and will therefore be very accessible to everyone.