4 research outputs found
Separating the Communication Complexity of Truthful and Non-Truthful Combinatorial Auctions
We provide the first separation in the approximation guarantee achievable by
truthful and non-truthful combinatorial auctions with polynomial communication.
Specifically, we prove that any truthful mechanism guaranteeing a
-approximation for two buyers with XOS
valuations over items requires
communication, whereas a non-truthful algorithm by Dobzinski and Schapira [SODA
2006] and Feige [2009] is already known to achieve a
-approximation in communication.
We obtain our separation by proving that any {simultaneous} protocol ({not}
necessarily truthful) which guarantees a
-approximation requires communication
. The taxation complexity framework of
Dobzinski [FOCS 2016] extends this lower bound to all truthful mechanisms
(including interactive truthful mechanisms)