False-name-proofness with Bid Withdrawal

TL;DR

This paper introduces a new concept called false-name-proofness with withdrawal (FNPW) in Internet auctions, addressing a more powerful manipulation where agents can submit and later withdraw false identities to influence outcomes.

Contribution

It defines FNPW, a stronger condition than false-name-proofness, and proposes a mechanism to prevent beneficial false-name manipulations involving withdrawal.

Findings

FNPW is a strictly stronger condition than FNP.

The paper formalizes the concept of withdrawal in false-name manipulation.

Mechanisms satisfying FNPW prevent beneficial withdrawal strategies.

Abstract

We study a more powerful variant of false-name manipulation in Internet auctions: an agent can submit multiple false-name bids, but then, once the allocation and payments have been decided, withdraw some of her false-name identities (have some of her false-name identities refuse to pay). While these withdrawn identities will not obtain the items they won, their initial presence may have been beneficial to the agent's other identities. We define a mechanism to be false-name-proof with withdrawal (FNPW) if the aforementioned manipulation is never beneficial. FNPW is a stronger condition than false-name-proofness (FNP).