Robust Screens for Noncompetitive Bidding in Procurement Auctions
发现日本采购拍卖中中标价孤立、缺少接近的未中标价这一可疑模式，并基于此开发了允许一般信息结构和非平稳未观测异质性的竞争行为检验方法，实证表明该方法能识别数据中的其他可疑模式。
We document a novel bidding pattern observed in procurement auctions from Japan: winning bids tend to be isolated, and there is a missing mass of close losing bids. This pattern is suspicious in the following sense: its extreme forms are inconsistent with competitive behavior under arbitrary information structures. Building on this observation, we develop systematic tests of competitive behavior in procurement auctions that allow for general information structures as well as nonstationary unobserved heterogeneity. We provide an empirical exploration of our tests, and show they can help identify other suspicious patterns in the data.