04 Flexible-Indeterminate-Factor-Based-Asset-Allocation 2016
The paper introduces Flexible Indeterminate Factor‑Based Asset Allocation (FIFAA), a hybrid asset‑allocation methodology that blends modern portfolio theory, factor investing, reference‑portfolio mapping, and best‑ideas overlays. After reviewing a wide range of existing allocation approaches and their practical shortcomings, the authors propose a four‑step process: (1) select a parsimonious set of systematic factors (typically 4‑6) that capture an institution’s risk‑return objectives and are tradable; (2) map asset classes or investment universes to these factors using a linear exposure matrix, estimated via parsimonious statistical techniques (stepwise regression, LASSO) and refined with expert judgment; (3) choose desired factor exposures through quantitative methods (mean‑variance, Black‑Litterman, risk‑parity, etc.) while allowing for institutional views; and (4) translate the target factor exposures into concrete asset‑class weights. Because the number of asset classes exceeds the number of factors, the final step is indeterminate: the authors present three ways to resolve it – (a) a pure best‑ideas approach, (b) generating a large set of admissible portfolios via pseudo‑inverse solutions and filtering by constraints, and (c) a second‑stage optimization that treats factor exposures as hard constraints and incorporates preference scores or cost penalties. The framework also includes a robust rebalancing procedure that adds stochastic error to the exposure matrix, generates many candidate portfolios, and derives asset‑class ranges (e.g., 25th‑75th percentiles). The discussion highlights FIFAA’s ability to combine quantitative rigor with qualitative flexibility, acknowledges limitations (e.g., difficulty of estimating factor exposures, reliance on mean‑variance, mapping uncertainty, lack of back‑testing), and outlines future research directions. An appendix provides a method for correcting single‑factor betas to obtain unbiased multi‑factor betas.
Topics
FIFAA Four‑Step Process Overview
High‑level description of the four sequential steps: factor selection, asset‑class‑to‑factor mapping, target factor exposure determination, and asset‑class portfolio construction.