Glide-path design moves retirement outcomes more than private market allocations

What's New

The design of a defined contribution plan moves retirement outcomes as much as or more than its private market allocation, according to a CFA Institute research paper. The authors modeled a target-date fund over a 40-year career. A 10% private equity allocation, the strongest single option, lifted the average end balance above a stocks-and-bonds baseline. The gain was 13%. Cutting the horizon by 10 years mattered far more. Average balances fell by around 65%. Sponsors should settle contributions, horizon and glide path before picking a private asset sleeve.

Why It Matters

Asset managers pitching private assets for 401(k) defaults are selling the allocation as the lever. The paper finds the plan around it carries more weight. It also challenges the view that regulatory safe harbor, on its own, will improve outcomes. The authors call it insufficient. The US Department of Labor's proposed rule reduces litigation risk for fiduciaries. Fees, liquidity and valuation remain, and the authors name those guardrails as the ones that decide results.

By The Numbers

• 0.531 was the mean annual Sharpe ratio for the private equity fund, the highest of any single allocation. The baseline scored 0.462.

• $1.293 million was the average end balance for the infrastructure fund, the lowest in the group. Its Sharpe ratio still beat the baseline because volatility fell.

• 22 to 26% was the rise in average end balances across all funds when the paper halved the equity-to-bond transition period.

Reality Check

Several modeling choices limit how far the results travel.

• The target-date fund is synthetic. It assumes exposure can be adjusted at quarterly rebalancing, which fits evergreen structures better than closed-end funds.

• Private market returns come from PitchBook indexes of closed-end drawdown funds, net of fees. The authors desmoothed them because appraisal-based marks can overstate risk-adjusted returns.

• The data covers 15 years, a period that captures the post-crisis expansion of private markets.

• A bootstrap test without the normality assumption produced lower end balances on every measure except the Sharpe ratio. The relative ranking held.

• The results exclude plan administration, trading and rebalancing costs. End balances are nominal and not adjusted for inflation.

The Wrap

Private assets add most when they come last in a plan's design. Contribution discipline, horizon and glide path set the size of the outcome. The private sleeve then tilts it toward growth or stability. The finding holds for savers who contribute without pause over a full career and weakens where real funds carry the fees, lags and liquidity gates the model excludes. The first target-date funds built under the proposed DOL rule will test it within a few years.