This paper addresses the case when stock market returns are assumed being generated through a factorial structure. High levels of idiosyncratic risk are shown to exist for most stocks on the US market, when CAPM or APT are used for the estimation of diversifiable risks. The presence of these...

Business surveys aim at getting, as quickly and as simply as possible, the recent and probable changes in economic activity. Answers to most of the questions are qualitative with three modalities (qualification of an evolution: up / stable / down). The qualitative indicators provided by these...