Benefits of Natural Tontines vs. Savings-Only Retirement Strategies (Model-Based Summary)

1) Welfare benefit vs savings-only: “Tontine Equivalent Wealth” (TEW)

The referenced work summarizes welfare implications using Tontine Equivalent Wealth (TEW): the additional initial wealth required under a no-tontine (savings-only) strategy to achieve the same modeled expected lifetime utility as a strategy with access to tontines.

Reported preliminary examples include TEW values of approximately 164.87% to 168.87% of initial wealth for a medium risk-aversion case (CRRA parameters ρ=γ=4) with a bequest motive (b=1) and tontine pool sizes N0=200 and N0=10,000. Interpreting TEW as a welfare-equivalent wealth uplift, this implies that under these modeled scenarios, a savings-only retiree would require roughly ~65% to ~69% more initial wealth to match the lifetime utility achievable with tontine access.

TEW (as reported) increases with larger pool sizes (less volatile mortality credits) and increases with higher risk aversion in the reported examples, reflecting the value of improved risk-sharing relative to self-insuring longevity risk through savings alone.

2) Why tontines can improve outcomes: age-increasing mortality credits

The referenced work depicts mortality credits as a return component that generally increases with age and has a volatility that decreases with pool size. This provides an economic mechanism for stronger late-life consumption capacity among survivors compared to a savings-only strategy.

3) Consumption smoothing without requiring an annuity in the illustrated setup

Model illustrations show that access to tontines can support consumption smoothing across retirement years, with increasing support at advanced ages. In the depicted figures, the tontine mechanism supports smoothing without requiring a separate tontine annuity product in the presented setup.

4) Tradeoffs and heterogeneity: bequests, risk aversion, and pool size

• Bequest motives: Stronger bequest motives reduce the attractiveness of tontine allocations in the model because tontine balances generally do not contribute to bequests in the same way as individual savings accounts.
• Risk aversion: Higher risk aversion increases modeled allocation to tontines and increases the welfare value of tontine access in the reported examples.
• Pool size: Smaller pools yield more volatile mortality credits and may be less attractive than larger pools, all else equal.