Monday, February 12, 2007

Asset Allocation and Immediate Annuitization

The potential benefits of combining immediate annuities to portfolio withdrawal strategies is examined in the following papers. In the first paper, Optimizing the Retirement Portfolio: Asset Allocation, Annuitization, and Risk Aversion, the authors consider the following withdrawal strategies:
  • Fixed dollar withdrawals
  • Fixed percentage withdrawals
  • Percentage withdrawals to longest mortality table (1/T)
  • The MRD withdrawal (1/E(T)
  • Total immediate annuitization
  • Partial annuitization
Optimizing the Retirement Portfolio: Asset Allocation, Annuitization, and Risk Aversion

Horneff, Wolfram J., Mitchell, Olivia S., Maurer, Raimond and Dus, Ivica, "Optimizing the Retirement Portfolio: Asset Allocation, Annuitization, and Risk Aversion" (July 2006). Pension Research Council (PRC) Working Paper

Retirees must draw down their accumulated assets in an orderly fashion so as not to exhaust their funds too soon. We derive the optimal retirement portfolio from a menu that includes payout annuities as well as an investment allocation and a withdrawal strategy, assuming risk aversion, stochastic capital markets, and uncertain lifetimes. The resulting portfolio allocation, when fixed as of retirement, is then compared to phased withdrawal strategies such a "self-annuitization" plan or the 401(k) "default" pattern encouraged under US tax law. Surprisingly, the fixed percentage approach proves appealing for retirees across a wide range of risk preferences, supporting financial planning advisors who often recommend this rule. We then permit the retiree to switch to an annuity later, which gives her the chance to invest in the capital market and "bet on death." As risk aversion rises, annuities first crowd out bonds in retiree portfolios; at higher risk aversion still, annuities replace equities in the portfolio. Making annuitization compulsory can also lead to substantial utility losses for less risk-averse investor.

In a second paper, Moshe Milevsky examines the economics of delayed annuitization, including the timing effects of having inflation escalating and variable account annuitization options.

Optimal Asset Allocation and The Real Option to Delay Annuitization: It’s Not Now-or-Never

Moshe A. Milevsky and Virginia R. Young
Version: 13 April 2002

Asset allocation and consumption towards the end of the life cycle is complicated by the uncertainty associated with the length of life. Although this risk can be hedged with life annuities, empirical evidence suggests that voluntary annuitization amongst the public is not very common, nor is it well understood. This paper develops a normative model of when, and if, one should purchase an immediate life annuity. This problem is particularly relevant given the increasing number of Defined Contribution pension plans in the U.S – for which participants must make this decision – and the corresponding trend away from Defined Benefit guarantees. Specifically, our main qualitative argument is that there is a real option – akin to the corporate finance usage of the word – embedded in the decision to annuitize. A life annuity can be viewed as a project with a positive net present value. However, quite distinct from a fixed-income bond or period certain annuity, once purchased, a life annuity can never be sold, reversed, or exchanged. Its purchase is final because of the severe moral hazard involved in trying to terminate a life-contingent claim. We use standard continuous-time technology to solve the optimal asset allocation and annuitization timing problem. We then define the value of the real option to defer annuitization (RODA) as the compensating utility loss from being unable to behave optimally. By using reasonable capital market and actuarial parameters, we estimate that the real option to defer annuitization is quite valuable until the mid-70s or mid-80s. Of course, the precise values depend on one’s gender, risk aversion, and subjective health assessment. Finally, we show that low-cost variable immediate annuities, which are currently not widely available, greatly reduce the option value to wait and create substantial welfare gains. This might explain the large number of TIAA-CREF participants who rightfully choose to annuitize their DC pension plan, as a result of the availability of both fixed and variable payments in the payout stage.

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