Illinois Walls: how barring indirect purchaser suits facilitates collusion
分析美国最高法院1977年伊利诺伊砖案规则，该规则限制只有直接购买者才能提起反垄断损害赔偿诉讼，但研究发现这一规则反而助长了上游卡特尔合谋，因为卡特尔可以通过低价配给投入品，将部分利润转移给直接购买者，从而使其放弃起诉。
In its landmark ruling in Illinois Brick Co. v. Illinois in 1977, the U.S. Supreme Court restricted standing to sue for recovery of antitrust damages to direct purchasers. However, antitrust damages are typically (in part) passed on to intermediaries lower in the chain of production and ultimately to consumers. We show that the Illinois Brick rule facilitates collusion. It allows an upstream cartel to shield itself from private damage claims by forwarding a share of cartel profits to its direct purchasers. These benefits dissuade the direct purchasers from exercising their exclusive right to sue for private damages. The cartel can achieve this by rationing inputs at low prices. Several U.S. antitrust cases show symptoms of “Illinois Walls .”