In standard auctions resale creates a role for a speculator-a bidder who is commonly known to have no use value for the good on sale. We study this issue in environments with symmetric independent private-value bidders. For second-price and English auctions the efficient value-bidding...

The English auction is susceptible to tacit collusion when post-auction interbidder resale is allowed. We show this by constructing equilibria where, with positive probability, one bidder wins the auction without any competition and divides the spoils by optimally reselling the good to the other...