We investigate a market thickness–market power tradeoff in an auction setting with endogenous entry. We find that charging admission fees can sometimes dominate the benefit of recruiting additional bidders, even though the fees themselves implicitly reduce competition at the auction stage. We also highlight that admission fees and reserve prices are different instruments in a setting with uncertainty over entry costs, and that optimal mechanisms in such settings may be more complex than simply setting a reserve price. Our results provide a counterpoint to the broad intuition of Bulow and Klemperer (1996) that market thickness often takes precedence over market power in auction design.

我们研究了具有内生进入的拍卖环境中的市场厚度-市场力量权衡。我们发现收取入场费有时可以支配招募额外投标人的好处，即使费用本身隐含地减少了拍卖阶段的竞争。我们还强调，入场费和底价在进入成本不确定的情况下是不同的工具，在这种情况下，最佳机制可能比简单地设定底价更复杂。我们的结果与 Bulow 和 Klemperer (1996) 的广泛直觉相反，即在拍卖设计中市场厚度通常优先于市场力量。