%0 Journal Article %A Paul A. Samuelson %T The judgment of economic science on rational portfolio management %B Indexing, timing, and long–horizon effects %D 1989 %R 10.3905/jpm.1989.409238 %J The Journal of Portfolio Management %P 4-12 %V 16 %N 1 %U https://jpm.pm-research.com/content/iijpormgmt/16/1/4.full.pdf