Detecting Bidders Groups in Collusive Auctions
研究了公共采购中按修剪平均价授标的拍卖，提出统计检验方法检测竞标者的协调行为，并在法院确认合谋的数据集上验证了方法的有效性。
We study entry and bidding in procurement auctions where contracts are awarded to the bid closest to a trimmed average bid. These auctions, common in public procurement, create incentives to coordinate bids to manipulate the bid distribution. We present statistical tests to detect coordinated entry and bidding choices. The tests perform well in a validation dataset where a court case makes coordination observable. We use the tests to detect coordination in a larger dataset where it is suspected, but not known. The results are used to interpret a major market shakeout following a switch to first price auctions.