12 Private Value Auctions: A First Look
willing to pay for the object. Each X
i
is independently and identically distributed
on some interval [0, ω] according to the increasing distribution function F.
It is assumed that F admits a continuous density f ≡F
and has full support.
We allow for the possibility that the support of F is the nonnegative real line
[0,∞) and if that is so, with a slight abuse of notation, write ω =∞. In any case,
it is assumed that E
[
X
i
]
< ∞.
Bidder i knows the realization x
i
of X
i
and only that other bidders’ values
are independently distributed according to F. Bidders are risk neutral; they seek
to maximize their expected profits. All components of the model other than the
realized values are assumed to be commonly known to all