To prevent issuers from inflating their share prices, SEC Rule 10b-18 sets price ceilings on share repurchases through open markets. We find that market-structure reforms in the 1990s and 2000s dramatically increased share repurchases because they relaxed constraints on issuers competing with other buyers under price ceilings. The Tick Size Pilot Program, a controlled experiment that partially reversed previous reforms, significantly reduced share repurchases. We estimate that price ceilings and reduced market-structure frictions explain 18% of the secular increase in share repurchases. Meanwhile, these two frictions still exist, which explains why share repurchases have not crowded out dividends entirely.

中文翻译：

---

价格上限、市场结构和支付政策

为了防止发行人抬高股价，SEC 规则 10b-18 规定了通过公开市场回购股票的价格上限。我们发现，20世纪90年代和2000年代的市场结构改革极大地增加了股票回购，因为它们放松了对发行人在价格上限下与其他买家竞争的限制。 “Tick Size Pilot Program”是一项受控实验，部分扭转了之前的改革，大幅减少了股票回购。我们估计，股票回购长期增长的 18% 归因于价格上限和市场结构摩擦的减少。与此同时，这两方面的摩擦仍然存在，这也解释了为什么股票回购并没有完全挤占股息。