Stock Splits in Switzerland: To Signal or Not to Signal?
利用瑞士两次降低法定最低面值后公司可自由拆分的自然实验，区分了传递股价永久上涨信号的拆分与仅因监管变化而进行的拆分，发现前者带来显著更高的回报，且拆分后相对最小报价单位增大、买卖价差常扩大。
In Switzerland, the existence of a mandatory minimum par value inhibited many companies from splitting their stocks as they already traded at their minimum par value. These Swiss companies could split their stocks only after the legal minimum par value was lowered in July 1992 and again in May 2001. These two events provide rare opportunities to distinguish between stock splits that signal a permanent increase in stock price and splits that are merely a reaction to a regulatory change and thus have other motives. The significant return differences between the two samples are in line with the hypothesis that splits are a means to send positive signals to the stock market. Furthermore, while trading volumes remained largely unaffected after stock splits, relative tick sizes generally increased after a stock split, and bid‐ask spreads often increased after a stock split.