Mario Szegedy (Theory Seminar S14)

szegedy.jpg"Impossibility Theorems and the Universal Algebraic Toolkit"
Mario Szegedy
Monday, April 14th, 2014, 2:00 pm
EBU3B, Room 4140
We elucidate a close connection between the Theory of Judgment Aggregation and a relatively young but rapidly growing field of universal algebra, that was primarily developed to investigate constraint satisfaction problems. We show that theorems in the above field translate (often directly) to impossibility, classification and robustness theorems in social choice theory. We refine the classification of E. Dokow, R. Holzman of binary evaluations, give a classification theorem for the majoritarian aggregator and show how Sen’s well known theorem follows from it, add new classification results to non binary evaluations, define new aggregator classes and also prove theorems about them.