FPSB Auctions
6.0.1
– We use Perfect Bayesian Nash equilibrium in pure strategies
– denote the equilibrium bid as Bi, with realisation bi. Let B = {B1, ..., Bn}
– assume affiliation for this section and also take no stand on private vs common values
– we assume some regularity (see Athey and Haile for details). Notably that values lie on some compact subset of the real line
– we would like some existence and uniqueness results to proceed: Here is what exists
– Existence:
∗ ∃ an equilibrium with strictly increasing strategies except in some CV auctions with asymmetric bidders
– Uniqueness:
∗ ∃ a unique equilibrium in strictly increasing strategies in PV auctions as long as we
have independence or symmetry (or both)
– In CV formats we tend to assume what we need. Note that we don’t really need unique- ness, we just need everyone to be playing the same strictly increasing equilibrium