Michael Z. Stamos

Variable payout annuities and dynamic portfolio choice in retirement

Many retirees hope to continue earning capital market rewards on their saving while avoiding outliving their funds during retirement. We model a dynamic utility maximizing investor who seeks to benefit from holding both equity and longevity insurance. She is free to adjust her portfolio allocation of her financial wealth as well as of the annuity over time, and she can purchase variable payout annuities any time and incrementally. In this setting, we show that the retiree will not fully annuitize even without bequests; rather, she will combine variable annuities with withdrawals from her liquid financial wealth so as to match her desired consumption profile. Optimal stock exposures decrease over time, both within the variable annuity and the withdrawal plan. Welfare gains from this strategy can amount to 40% of financial wealth, depending on risk parameters and other resources; additionally, many retirees will do almost as well as the fully optimized outcome if they hold variable annuities invested 60/40 in stocks/bonds.

Optimal Gradual Annuitization: Quantifying the Costs of Switching to Annuities

We compute the optimal dynamic annuitization and asset allocation policy for a retiree with Epstein/Zin preferences, uncertain investment horizon, potential bequest motives, and pre-existing pension income. In our setting the retiree can decide each year how much he consumes and how much he invests in stocks, bonds, and life annuities, while the prior literature mostly considered restricted so-called deterministic or stochastic switching strategies. We show that postponing the annuity purchase is no longer optimal in the gradual annuitization case since investors are able to attain the optimal mix between liquid assets (stocks and bonds) and illiquid life-annuities each year. In order to assess potential utility losses, we benchmark various restricted annuitization strategies against the unrestricted gradual annuitization strategy.

Total Return Strategies for Multi-Asset Portfolios

Traditional balanced funds with a more or less constant stock allocation cannot solve the conflict of the varying investment horizons most institutional investors face. To generate capital gains, the investor must accept large allocations in risky asset classes like equities, which is often difficult to reconcile with short-term requirements such as avoiding annual losses. One way around this problem is a risk-based total return strategy that explicitly controls for shortfall risk and at the same time uses the available risk budget effectively to enhance performance potential in the long run. Because such a strategy allows for greater shifts in asset class weights over time, it can start with larger allocations to stocks or other risky asset classes than static strategies. An extensive simulation study comparing this risk-based strategy to several dynamic asset allocation approaches in a backtest quantifies its short-run hedging effectiveness and long-run hedging costs.

Money in Motion: Dynamic Portfolio Choice in Retirement

Retirees confront the difficult problem of how to manage their money in retirement so as to not outlive their funds while continuing to invest in capital markets. We posit a dynamic utility maximizer who makes both asset location and allocation decisions when managing her retirement financial wealth and annuities, and we prove that she can benefit from both the equity premium and longevity insurance in her retirement portfolio. Even without bequests, she will not fully annuitize; rather, her optimal stock allocation amounts initially to more than half of her financial wealth and declines with age. Welfare gains from this strategy can amount to 40 percent of financial wealth (depending on risk parameters and other resources). In practice, it turns out that many retirees will do almost as well by purchasing a variable annuity invested 60/40 in stocks/bonds.