%0 Journal Article %A Kenneth J Winston %T Performance Measurement Manipulation %D 2005 %R 10.3905/jpm.2005.500366 %J The Journal of Portfolio Management %P 101-108 %V 31 %N 3 %X Single scalar measures of portfolio performance are inevitably susceptible to manipulation. The Morningstar stars awarded to mutual funds on the basis of huge flows into or out of funds are an example. The system was updated in 2002 and corrects a number of problems with the older system, but—like any single scalar measure—it can be gamed. %U https://jpm.pm-research.com/content/iijpormgmt/31/3/101.full.pdf