Title: Market efficiency: an information entropy perspective
Authors: Imen Mahmoud; Kamel Naoui
Addresses: Faculty of Economic Sciences and Management of Tunis, University of Tunis El Manar, Campus Farhat Hached - B.P. no. 94 Rommana, Tunis 1068, Tunisia ' Business School of Tunis, University of Manouba, Campus Universitaire de La Manouba, Manouba 2010, Tunisia
Abstract: The aim of this paper is to examine the market efficiency from an information entropy perspective. Specifically, we compare some emerging and developed markets to pinpoint efficiency of these markets in time. We also used the symbolic time series analysis to detect dynamics of the processes under investigation over the period 2003-2013. The results indicate that these markets show a dynamic market efficiency unlike what static tests seem to suggest. Moreover, emerging and developed markets are less efficient. This lower efficiency comes in parallel with crisis periods (financial or political). When the market is efficient, market returns move following a random position and information entropy reaches its maximum. However, when an event is particular, entropy decreases and the market is considered inefficient. When the market is inefficient, prices do not instantly reflect new information, which replicates an information comprehension process, through a learning process that is considered time-consuming.
Keywords: crisis; information approach; knowledge; learning; market efficiency; Shannon entropy.
International Journal of Management and Enterprise Development, 2018 Vol.17 No.2, pp.95 - 120
Received: 11 Feb 2017
Accepted: 30 Apr 2017
Published online: 28 Mar 2018 *