Lifecycle investing is the practice of setting a retirement portfolio's asset allocation by investor age, typically shifting from stocks toward bonds as retirement nears. Anarkulova, Cederburg, and O'Doherty (2023) bootstrapped 31,801 GFDatabase country-month returns from 39 developed countries (1890–2023) to optimize a US couple's portfolio. The optimal weights stayed near one-third domestic stocks and two-thirds international stocks at every age, with no material fixed income allocation. Their paper, "Beyond the Status Quo: A Critical Assessment of Lifecycle Investment Advice," finds target-date fund investors need 63% more pre-retirement savings to match it.
What the Study Found
Averaged from age 25 to 95, the optimal age-based strategy held 99% equity, split 31% domestic and 69% international stocks. The one exception came at retirement: bills took 27% at age 65, falling to 7% by age 68 and 0% by age 70. A balanced portfolio of 60% domestic stocks and 40% bonds required a 19.44% savings rate to match the optimal strategy's 10.00%. Bonds returned 0.95% a year in real terms versus 7.03% for international stocks, and bonds' 30-year variance ratio was 2.30 versus 0.75. Under a domestic-only IID bootstrap, the age-65 portfolio instead held 38% domestic stocks, 14% bonds, and 48% bills.
"Our key finding is that the optimal age-based policy eschews fixed income investments in favor of an all-equity portfolio for nearly all of the lifecycle."
Anarkulova, Cederburg and O'Doherty (2023), Beyond the Status Quo: A Critical Assessment of Lifecycle Investment Advice, p. 19.
Methodology
The dataset is monthly real returns on domestic stocks, international stocks, government bonds, and bills, built from Global Financial Data's GFDatabase. It pools 31,801 country-month observations from 39 developed countries, and each strategy was simulated across 1,000,000 lifecycle outcomes. The sample spans 1890 to 2023, resampled with a stationary block bootstrap averaging 120-month blocks. The model controls for stochastic labor income, Social Security, longevity risk, a bequest motive, a 4% withdrawal rule, and no-leverage constraints.
Key Statistics
| Metric | Finding | Context |
|---|---|---|
| Optimal fixed-weight strategy | 33% domestic stocks, 67% international stocks, 0% bonds, 0% bills | Equivalent savings rate 10.07% versus the 10.00% age-based baseline |
| Equivalent savings rate, 100% bills | 56.71% | To match a 10.00% savings rate in the optimal age-based strategy |
| Equivalent savings rate, 100% domestic stocks | 16.42% | To match a 10.00% savings rate in the optimal age-based strategy |
| Probability of financial ruin, balanced 60/40 | 16.9% | 4% withdrawal rule; 38.9% for bills, 17.1% for domestic stocks |
| Correlation with inflation, 30-year returns | −0.78 (bonds) vs −0.01 (international stocks) | 39 developed countries, 1890 to 2023 |
| Highest price-dividend quintile allocation | 16% domestic stocks, 75% international stocks, 9% bonds | Market-timing extension; equivalent savings rate 9.73% |
| Borrowing at a 1.40% spread | 55% of wealth; 34% domestic and 66% international stocks | Leverage extension, Table VII Panel M |
| 50% belief in American exceptionalism | 60% US stocks, 40% international stocks | Mix of developed-country and US-only bootstrap samples |
| Household utility (Equation 1) | U(C, B) = Σ δ^t (C_t / √H_t)^(1−γ) / (1−γ) + δ^Tmax θ (B + k)^(1−γ) / (1−γ) | γ = 3.84, k = $490,000 in 2022 USD; summed over retirement months |
Optimal Age-Based Strategy vs Target-Date Fund
| Measure | Optimal age-based strategy | TDF |
|---|---|---|
| Mean wealth at retirement | $1.06 million | $0.77 million |
| Mean income replacement rate | 1.24 | 1.03 |
| Probability of financial ruin | 6.7% | 19.7% |
| Mean wealth at death | $2.66 million | $0.72 million |
| Median bequest | $0.96 million | $0.27 million |
| Average maximal retirement drawdown | 47% | 40% |
| 95th percentile retirement drawdown | 73% | 89% |
Why This Matters
Target-date funds, the dominant default in US workplace plans, are built on the stock-bond glidepath this paper tests. Savers reviewing a target-date fund can compare its bond sleeve and home-country tilt against the model's choices. An all-equity plan only works if the saver holds through deep interim losses, a behavioral risk the authors flag. Regulators defining qualified default options and plan sponsors choosing default funds are the audiences the paper names directly.