We study Roll's (1992) conjecture that there may exist an implicit value in index-tracking (IVIT) relative to forming mean-variance (MV) optimal portfolios under estimation error. While index-tracking portfolios are deemed MV inefficient ex-ante, it is unclear whether this is the case when...

This paper presents a new framework to model and calibrate the process of firm value evolution when an unanticipated exogenous event impacting one firm can contagiously affect other firms. The nature of propagation of such contagion is determined by the underlying connections between firms,...