Name the denominator before quoting a percentage explained by allocation.

Family Office Private Wealth Journal · Editorial research desk · 2 November 2026

Companion to Does Asset Allocation Policy Explain 40, 90, or 100 Percent of Performance? by Roger G. Ibbotson; Paul D. Kaplan.

Decision in practice

Two advisers disagree about how much performance asset allocation explains. One means variation through time; the other means differences between funds.

Committee assignment

Write the denominator and comparator before showing a percentage. Ask whether the question concerns levels, variation or excess returns.

Record and decision rule

Reject a dashboard headline that quotes an explained percentage without saying what quantity varies.

Illustrative application by the editorial desk. The source authors did not evaluate or endorse this procedure.