RT Journal Article SR Electronic T1 The World Market Wealth Portfolio* JF The Journal of Portfolio Management FD Institutional Investor Journals SP 5 OP 17 DO 10.3905/jpm.1983.408915 VO 9 IS 2 A1 Roger G. Ibbotson A1 Laurence B. Siegel YR 1983 UL https://pm-research.com/content/9/2/5.abstract AB