RT Journal Article SR Electronic T1 The discomforts of efficiency JF The Journal of Portfolio Management FD Institutional Investor Journals SP 1 OP 3 DO 10.3905/jpm.1987.409130 VO 14 IS 1 A1 Peter L. Bernstein YR 1987 UL https://pm-research.com/content/14/1/1.abstract AB