中文摘要
本文从理论和实验两方面考察在游说竞争中实施对称出价上限的福利含义。我们将游说博弈建模为包含两个激进派和一个中间派的抽奖式竞赛，其中所有参与人都严格偏好获胜；但若失败，激进派更希望输给中间派而非对方激进派。我们证明了均衡的存在性与唯一性，并发现：在没有出价上限的情况下，激进派的出价可能过于激进，以致将中间派挤出竞争，从而阻碍社会福利最大化结果的实现。因此，实施出价上限从两个方面提升社会福利：它降低了总支出，并提高了中间派获胜的可能性。我们的实验结果在性质上与理论预测一致。不过，我们也识别并讨论了若干值得注意的行为模式：与关于竞赛的大量实验文献（Sheremeta, 2013）相反，在所有处理中总出价均未超出理论预测。
Abstract
This article examines, both theoretically and experimentally, the welfare implications of implementing symmetric bid caps in lobbying competitions. We model lobbying games as lottery contests with two radicals and one centrist, where all players strictly prefer to win. However, if they lose, radicals prefer to lose to a centrist rather than to the opposing radical. We establish the existence and uniqueness of equilibrium and find that, in the absence of a bid cap, radicals may bid aggressively enough to drive the centrist out of the competition, thereby preventing the social welfare-maximizing outcome. Consequently, implementing a bid cap enhances social welfare in two ways: it reduces aggregate expenditure and increases the likelihood of the centrist winning. Our experimental results qualitatively align with the theoretical predictions. However, we also identify and address notable behavioral patterns: in contrast to the vast experimental literature (Sheremeta, 2013) on contests, aggregate bids do not exceed theoretical predictions in all treatments.