Strategic Retirement Planning in the Face of Uncertain Life Expectancy

Planning for retirement spending can be difficult, because you're not sure how many years you'll be retired for. Learn how life expectancy factors into retirement planning.
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Saving for retirement is tough. What you might not realize, though, is that spending your retirement money is also tough – at least, planning a sustainable strategy for retirement spending is.

Investment returns and the future cost of living are big enough uncertainties, but the greatest difficulty is not knowing how long you will be retired. This is a challenge because time has a huge impact on how much money you will need.

Saving for Retirement When Time Equals Money

When you sit down to figure out how much you need to save for retirement, one problem is not knowing how many years of retirement spending you need to fund. The average life expectancy in the U.S. is 78 years, but this average is pulled down by people who die young. If you make it to the traditional retirement age of 65, you can be expected to live not just another 13 years (to 78) but for an average of 18.7 years.

These figures are a moving target. In 40 years, from 1970 to 2010, the average U.S. life expectancy increased by 7.5 years. So, if you are a 25-year-old, there is no telling what your life expectancy might be by the time you reach retirement age in 40 years.

Remember, even if life expectancy figures were not so hard to pin down, these numbers are just averages that do not tell you with much accuracy how long you will actually live. Because they are averages, it means that roughly half the people will live longer than the typical life expectancy, which from a retirement funding standpoint means needing more money.

Another important aspect of the relationship between time and the money needed for retirement is that with every year, inflation will take another piece out of the value of your money. If you assume a 3 percent inflation rate, this impact might seem subtle from year to year, but at that rate, it would cut the value of your money in half every 24 years.

Which Banks Have the Best Savings Account Rates?

Savings rates are higher than they’ve been in 15 years, but if you’re using a traditional, big-name bank, you’re missing out on these rates.

Here are our top picks for those who want to earn the highest interest on their savings.

Planning Your Retirement Spending

The following are four common methods to plan for retirement spending when you are unsure of your future life expectancy:

Budget-Based Spending

One method of planning retirement spending is to make assumptions about your expenses based on your expected lifestyle and budget to spend a certain amount each year.

However, the problem with a fixed amount of retirement spending is that if your investment returns do not keep up, you will start drawing down your savings. As your savings diminish, your spending will become an increasingly large percentage of those savings, making it even harder for investment returns to keep up.

Unless you start out with a particularly large nest egg relative to the amount you spend, this is likely to result in you outliving the money in your savings account.

Harvesting Investment Gains

To avoid the above problem, you could simply spend the investment gains you make every year, but unless you are in very conservative investments, your returns are going to be very unpredictable from year to year, and sometimes they might be losses rather than gains. As a practical matter, you cannot simply suspend spending after a bad year, so this is not a reliable approach.

Living on Investment Income

Income can be more reliable than total returns on investments, but while income may produce positive returns, recent years have seen those returns diminish as savings account rates and bond yields have slid toward zero.

The 4% Rule of Thumb

Financial planners have long used 4% as the portion of savings that you can spend annually and have your investment returns generally replenish your spending and keep up with inflation. However, low yields in recent years have made even 4% a bit of a stretch, so you might want to aim for lower spending than that or face seeing your savings diminish over time.

Because guaranteed returns these days are meager, and higher returns are unpredictable, there is no best-of-both-worlds approach to planning retirement spending. The only way to deal with uncertainty is to be flexible.

Try to set a spending budget that is a low percentage (i.e., less than 4%) of your retirement savings. However, if you have investment success, don’t automatically raise your spending in line with the portfolio’s growth because you may need to keep some of that growth in reserve against future setbacks.

Conversely, if your investments do not do well, you should be quick to adjust spending down in line with any portfolio losses so that spending does not grow to be a disproportionate percentage of your savings.

Richard Barrington, a Senior Financial Analyst at MoneyRates, brings over three decades of financial services expertise to the table. His insightful analyses and commentary have made him a sought-after voice in media, with appearances on Fox Business News, NPR, and quotes in major publications like The Wall Street Journal and The New York Times. His proficiency is further solidified by the prestigious Chartered Financial Analyst (CFA) designation, highlighting Richard’s depth of knowledge and commitment to financial excellence.
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