top of page

The Flawed Accumulation-Deaccumulation Model of Retirement Planning


An article published last week represents what is likely the most widespread highly flawed conventional wisdom assumptions about retirement financial planning which is the “accumulation-deaccumulation” model.

The question commonly asked is “how much money do you need to retire?” A commercial on TV a few years ago asked “what is your number?” and featured people carrying around large orange numbers on their shoulders ranging from about $500,000 to about $2 million.

The dangerous accumulation-deaccumulation model assumes that you should accumulate a massive pile of money by trading stocks, bonds and other paper assets that can be bought and sold with the click of a mouse that generate commissions and administrative fees for large brokerage houses that have marble floors in their waiting rooms. Then when you retire, you are supposed to sell the paper assets (generating more commissions) at a rate (which used to be 4%) that will deplete the pile of money in such a manner that you will be able to buy food and medicine until you die after subtracting the amount of passive income you get from Social Security and/or the rare pension plan.

The accumulation-deaccumulation model also makes some ridiculous and dangerous assumptions such as that you should rely on a certain return for your investment portfolio, which is 8% per year at the brokerage house where I keep my limited portfolio of mutual funds. I wrote a blog article earlier this year dedicated to the dangers of that absurd assumption.

The actual performance of the S&P 500 over the past 20 years from 1999 to 2018 gave a non-impressive compounded return of 3.7%. If you don’t believe this number you can verify it for yourself.

In any case, articles such as these have the majority of the sheeple believing that the most important component of retirement planning is hitting the magic number for net worth, held in liquidatable assets (i.e., that you can access funds within 48 hours of a clock of a mouse), that you can spend down to meet your needs in retirement.

The fine print in many of these articles mentions the actuarial average age at which you should plan to die. I always wondered if they want you to die at that age or pray that your nest egg will somehow last longer if you last longer. But that is not the biggest flaw in the accumulation-deaccumulation model. Even inflation is not the biggest flaw in this model. Even the ridiculous assumption that you only need 70% of your pre-retirement income after you leave your job, is not the biggest flaw in this model.

The biggest flaw in the accumulation-deaccumulation model is that it relies on the assumption that you should plan to pay the balance of your daily living expenses after Social Security payments, from a large pile of cash that you must accumulate.

Let’s consider two hypothetical scenarios.

The first scenario will be based on the following assumptions:

  • A couple has one wage earner who starts at $30,000 per year at age 30

  • The wage earner’s salary increases by 3% per year and by age 65, the income is $84,400 (median household income in 2018 was $61,800)

  • The couple puts away 7.6% of their gross income every year into retirement savings (personal savings rate in the US during 2015-2019 ranged from 6.5% to 8.8% according to FRED = Federal Reserve Bank of St. Louis)

  • The compounded return on the investment of retirement savings is 5% (compare that to the 3.7% compounded return on the S&P 500 for the 20 years of 1999-2018). Under these assumptions, at age 65 the couple will have retirement savings of $329,900. The average retirement savings of Americans in their 60’s is $172,000 (this one data point already shows that Americans have major problems saving for retirement!).

  • The couple will spend 70% of their pre-retirement income after retirement (this is a common assumption…incorrect, but common)

  • The couple will receive $1,600 per month in Social Security payments starting at age 65 at which time the working spouse retires.

  • Inflation is intentionally ignored in this graph

The red curve in the graph shows the accumulation of retirement savings from age 30 through age 65 and the deaccumulation of retirement savings using the assumptions shown above.

The graph shows that the couple has nothing left at age 76!