Asymétrie d’information et marchés financiers : une synthèse de la littérature récente

Cet article est une synthèse des recherches récentes en matière d’asymétrie d’informations sur les marchés financiers. L’impact de différentes hypothèses sur l’existence et l’efficience informationnelle des équilibres est étudié. Le cas de la concurrence parfaite est d’abord analysé (Grossman et Stiglitz, 1980). Puis la concurrence imparfaite est analysée. On distingue deux cas, selon que le bruit qui empêche le prix d’être parfaitement révélateur provient d’une offre exogène (KyIe, 1985, 1989), ou d’une dotation aléatoire des agents informés (Glosten, 1989; Bhattacharya et Spiegel, 1990; Bossaerts et Hughson, 1991). Dans le premier cas, l’équilibre existe toujours. Dans le second cas, il n’existe que si le bruit est assez élevé ou si le support de sa distribution est borné.The impact of different hypotheses on the existence and informativeness of rational expectations equilibria is analyzed within a simple synthetic model. The case of perfect competition is first analyzed (Grossman and Stiglitz, 1980). Second imperfect competition with exogenous noise trading is studied (KyIe 1985, 1989). Informational efficiency is lower than in the previous case, because of the strategic behaviour of the insider. Third, imperfect competition without noise trader, but with unknown random endowments of the informed agent is analyzed (Glosten, 1989; Bhattacharya and Spiegel, 1990; Bossaerts and Hughson, 1991). In contrast with the previous case, equilibrium exists only if there is enough noise

EXA-2016-1S-MECANIZACIÓN AGRÍCOLA-1-2Par.pdf

Voting Advice Applications (VAAs) are Web tools that are used to inform increasing numbers of voters during elections. This increasing usage indicates that VAAs fulfill voters’ needs, but what these needs are is unknown. Previous research has shown that such tools are primarily used by young males and highly educated citizens. This suggests that VAAs are generally used by citizens who are already well-informed about politics and may not need the assistance of a VAA to make voting decisions. To analyze the functions that VAAs have for their users, this study utilizes unique user data from a popular Dutch VAA to identify different user types according to their cognitive characteristics and motivations. A latent class analysis (LCA) resulted in three distinct user types that vary in efficacy, vote certainty, and interest: doubters, checkers, and seekers. Each group uses the VAA for different reasons at different points in time. Seekers’ use of VAAs increases as Election Day approaches; less efficacious and less certain voters are more likely to use the tool to become informed