| This dissertation studies new bidding behaviors in richer environments where bidders can either communicate or intertemporally interact. We focus on such three perspectives as collusion, strategic information disclosure and intertemporal inference. In the collusion chapter, we propose a framework to investigate the structure of endogenous collusion and show that an endogenously formed ring shall in general be a partial ring. In the information disclosure chapter, we study the auctioneer's optimal choice of interperiod information release and show the standard sequential Dutch auction or the sequential first-price auction with the announcement of each stage's winning bid can generate the highest revenue among all considered sequential auction formats. In the intertemporal inference chapter, we suggest a resale explanation for the price path in sequential auctions with multi-unit demand. |