This paper reviews single object auctions when bidders? values of the object
are interdependent. We will see how the auction forms could be ranked in
terms of expected revenue when signals that bidders have about the value of
the object are affiliated. In the discussion that follows we will deal with
reserve prices and entry fees. Furthermore we will examine the conditions
that have to be met for English auction with asymmetric bidders to allocate
the object efficiently. Finally, common value auctions will be considered
when all bidders have the same value for the object.