Deciphering the Annuity Puzzle: Practical Guidance for Advisors

Economists love to try to explain why people may act irrationally; such “puzzles” inspire numerous researchers to probe their possible solutions. The annuity puzzle, which ponders why retirees do not buy more annuities, is a classic example. After describing the basic theory behind why this is so puzzling, I will address a variety of potential explanations, and then turn to the practical guidance the puzzle offers for advisors and their clients.

The annuity puzzle

Economists have long been mystified as to why people do not make greater use of single-premium immediate annuities, which provide income for life and protect against longevity risk. Often cited in connection with this bafflement are Menahem Yaari’s research from 1965 about spending for an uncertain lifetime and Franco Modigliani’s Nobel Prize acceptance speech addressing the subject in 1985. In his recent book, The 7 Most Important Equations for Your Retirement, Moshe Milevsky described the mystery in the words of Wharton professor Solomon Huebner, who first defined the basic puzzle in the 1930s:

The prospect, amounting almost to a terror, of living too long makes necessary the keeping of the entire principal intact to the very end, so that, as a final wind-up, the savings of a lifetime, which the owner does not dare to enjoy, will pass as an inheritance to others. In view of these facts, it is surprising that so few have undertaken to enjoy, without fear, the fruits of the limited competency they have succeeded in accumulating. This can be done only through annuities... Why exist on $600, assuming 3% interest on $20,000, and then live in fear, when $1,600 may be obtained annually at age 65, through an annuity for all of life and minus all the fear?

Theory behind the annuity puzzle

Economists describe the annuity puzzle as a problem of maximizing lifetime expected utility. This is similar to maximizing lifetime spending power, except that utility accounts for the diminishing increases in value provided by additional spending in any given time period. This justifies the idea of smoothing spending over one’s lifetime. Higher spending in one year and lower spending in the next will provide less utility than if one evens out one’s spending over time. The gain in utility from spending more in the bad year outweighs the loss in utility from spending less in the good year, making one better off overall.

Other assumptions used to define the annuity puzzle include the notion that retirees do not care about leaving a bequest. They only wish to maximize their lifetime income. What’s more, there is assumed to be no investment risk. Financial markets are simplified to one asset, which always and forever provides the same fixed return to its owners. Of course the assumption of a fixed return is not realistic, but this assumption allows us to focus specifically on the role played by uncertain life spans.