The directional distance function model is a generalization of the radial model in data envelopment analysis (DEA). The directional distance function model is appropriate for dealing with cases where undesirable outputs exist. However, it is not a units-invariant measure of efficiency, which...

Purpose Using the sample between 2005 and 2011, the purpose of this paper is to investigate the effect of a new fund entry on incumbents using the overlap measure in portfolio holdings. Design/methodology/approach Empirical methodology is used in this study. Findings The authors find that...