This paper studies a first‐price common‐value auction in which bidders do not know the number of their competitors. In contrast to the case of common‐value auctions with a known number of rival bidders, the inference from winning is not monotone, and a “winner's blessing” emerges at low bids. As a result, bidding strategies may not be strictly increasing, but instead may contain atoms. Moreover, an equilibrium fails to exist when the expected number of competitors is large and the bid space is continuous. Therefore, we consider auctions on a grid. On a fine grid, high‐signal bidders follow an essentially strictly increasing strategy, whereas low‐signal bidders pool on two adjacent bids on the grid. The solutions of a “communication extension” based on Jackson, Simon, Swinkels, and Zame (2002) capture the equilibrium bidding behavior in the limit, as the grid becomes arbitrarily fine.

This paper analyzes a search model with asymmetric information of the common values variety. The basic features of this environment resemble those of a common values (procurement) auction, except that the searcher in our model, who is the counterpart of the auctioneer in the auction model, encounters trading partners through costly sequential search. The main objective is to understand how the combination of search activity and information asymmetry affects prices and welfare. We specifically inquire about the extent of information aggregation by the price –how close the equilibrium prices are to the full information prices–when the search frictions are small. Roughly speaking, we conclude that information is aggregated less well in the search environment than it is in the corresponding auction environment. We trace this to a stronger form of winner’s curse that is present in the search scenario. This understanding is a central qualitative insight of this paper, which is likely to have implications beyond the narrow confines of our model. We also look at the efficiency perspective and examine the relations between total surplus and the informativenss of the signal technology available to the uninformed. We conclude that total surplus is not monotone in the quality of the signals.

Most of the literature that studies frictional search‐and‐matching models with heterogeneous agents and random search investigates steady state equilibria. Steady state equilibrium requires, in particular, that the flows of agents into and out of the population of unmatched agents balance. We investigate the structure of this balance condition, taking agents' matching behavior as given. Building on the “fundamental matching lemma” for quadratic search technologies in Shimer and Smith (2000), we establish existence, uniqueness, and comparative statics properties of the solution to the balance condition for any search technology satisfying minimal regularity conditions. Implications for the existence and structure of steady state equilibria in the Shimer–Smith model and extensions thereof are noted. These reinforce the point that much of the structure of search‐and‐matching models with quadratic search technologies carries over to more general search technologies.