Alex Cukierman, Thomas Lustenberger, 04 November 2018

Almost 60 years ago, John Muth introduced the idea that adaptive expectations are rational if they efficiently use all available information. However, individuals are never fully certain, even ex post, about the permanence of economic developments. Using Israeli data, this explores the implications of this residual uncertainty for market efficiency. The findings point to issues with conventional market efficiency tests where ‘permanent-transitory confusion’ is in effect. 

Bastian Von Beschwitz, Donald Keim, Massimo Massa, 02 July 2015

High-frequency news analytics can increase market efficiency by allowing traders to react faster to new information. One concern about such services is that they might provide a competitive advantage to their users with potential distortionary price effects. This column looks at how high frequency news analytics affect the stock market, net of the informational content that they provide. News analytics improve price efficiency, but at the cost of reducing liquidity and with potentially distortionary price effects.

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