## Speaker:

Girish Varma
Tata Institute of Fundamental Research
School of Technology and Computer Science
Homi Bhabha Road
<br

## Time:

Tuesday, 17 May 2011 (All day)

## Venue:

- A-212 (STCS Seminar Room)

This talk will be an introduction to Social Choice Theory, which analyses methods to combine preferences of large number of voters to obtain a result that is fair . We will define some reasonable conditions for fairness, and prove the Arrows Impossibility theorem which states that no voting system can satisfy all these conditions.

References: This theory has been used to analyse an alternative voting scheme in UK, where a recent referendum about it was held

(see http://www.youtube.com/watch?feature=player_embedded&v=NS84zuf5_LQ#at=191).

Amartya Sen's Nobel Lecture

(http://nobelprize.org/nobel_prizes/economics/laureates/1998/sen-lecture.pdf)

Proof of Arrows Theorem

(http://home.uchicago.edu/~preny/papers/arrow-gibbard-satterthwaite.pdf)