Why did NASDAQ Market Makers Stop Avoiding Odd-Eighth Quotes?
1994年媒体报道做市商可能合谋维持价差后，纳斯达克活跃股票做市商迅速增加八分之一奇数报价，使价差下降近50%。本文用个股数据证明几乎所有做市商同步改变了报价行为。
On May 26 and 27, 1994, several national newspapers reported the findings of Christie and Schultz (1994) who cannot reject the hypothesis that market makers of active NASDAQ stocks implicitly colluded to maintain spreads of at least $.25 by avoiding odd-eighth quotes. On May 27, dealers in Amgen, Cisco Systems, and Microsoft sharply increased their use of odd-eighth quotes, and mean inside and effective spreads fell nearly 50%. This pattern was repeated for Apple Computer the following trading day. Using individual dealer quotes for Apple and Microsoft, we find that virtually all dealers moved in unison to adopt odd-eighth quotes.