Les marchés financiers sont-ils rationnels ?
Due to the recent stock market crises, many economists have been keeping aloof from the « core» of financial theory, whose main contention is that stock market prices are at any moment the best possible estimate of the « true» value of the issuing firms. Most of those economists have brought forward, in a way or another, the hypothesis that markets suddenly get crazy. This contribution, based on both observa~tion of the recent financial history (the crash of the « New Economy» securities) and results from « experimental economics», and using the complementary concepts of « mimicry» and « convention » to account for « self-referential dynamics», is opening a third way of thinking the efficiency problematic: investors fix their strategy based on the estimates of the other participants, even if they strongly believe they are wrong.
Approches de la genèse des comportements mimétiques sur le marché des actions
Cette these porte sur la comprehension de la genese des comportements imitatifs, sur les marches financiers. Apres une revue de la litterature, le developpement du modele de charfstein et Stein (1990) permet de structurer differentes hypotheses autour d'un comportement apprehende comme binaire : suivre ou s'opposer aux autres agents. Face a l'impossibilite de distinguer l'imitation a travers des tests econometriques, deux approches empiriques alternatives sont successivement abordees. Tout d'abord un questionnement exploratoire de gerants de portefeuille apportant des temoignages enrichissants sur cette problematique, puis une demarche experimentale, inspiree de Cote et Sanders (1997), permettant de mieux estimer les parametres du modele. La principale contribution de cette recherche est d'apporter des elements empiriques concrets sur le comportement imitatif reel et ses causes. Les deux facteurs essentiels mis en evidence dans ces demarches sont (1) l'importance de la preservation de la reputation du gerant, apportant du credit aux modeles fondes sur la theorie de l'agence, et (2) la correlation inverse entre les comportements mimetiques et les capacites des acteurs.
Did the metamorphosis from Export Processing Zones to Special Economic Zones improve the efficiency of trade enclaves in India?
In this paper, the efficiency of seven conventional Special Economic Zones in India is analyzed, by adopting a stochastic production frontier technique, for the period between 1986–1987 and 2007–2008.Results indicate that although the efficiency scores of these enclaves have improved over the years, specifically with the introduction of the SEZ policy (2000–2001), it is far below the threshold level as identified in the literature. Besides, one can also observe a discrepancy emerging between better export earning zones and efficient zones. On the determinants side, policy intervention and large geographical area, accompanied by clustering of units, are found to have impacted the efficiency scores of these enclaves positively.