Enough to Retire?

Just came across the 10/10/4 model as presented at Mint.com. It demonstrates a pretty tenuous grasp of reality.

Comments below.

Jess:the life expectancy in the US is only 77 years according the the CDC

Is the current life expectancy or the life expectancy for people who are currently 20 and won't hit 77 for another 50+ years? Do we have a link for this?

Even if we change the model to 80 years (let's give medical science a little credit), that still leaves us with 45 years of working to 35 years of not working. That leaves us with 45 people working for 35 people not working.

Imagine that you're living in a (global) village with 80 people. 45 of those people do all of the hunting / gathering / farming / house-building. The other 35 people are either non-productive children or old people who sit around smoking pipes and eating food brought in by the other 45 people.

Either way.

If you save 10% / year for 45 years, and receive no effective pay raise between 20 & 65 (i.e.: pay raise = inflation). Then you would need ~3.25% real returns (that's returns above inflation) for basically the entire 45 years to meet the goal of having 10x your annual income. That doesn't sound like much, but here's some perspective.

Right now TIPS bonds are offering 0.7% real returns (they were offering 0.0% returns just a few months ago). Real Stock market returns over the last decade are into the negative. If you earn 0% real returns one year you have to make 7.5%+ real returns the next, just to make it up, that's not easy.

What's more, you're subject to a very critical period. At year 30 you have about 5x of your 10x. From year 30 to 45, you're only going to save 1.5x (putting you at 6.5x), which means that you're relying on 15 years of solid returns to make up that other 3.5x. If you have a 5 or 10-year drought, you could end up way short. And a 5 or 10-year drought is going to happen somewhere in those 45 years.

Finally, we made the very unsafe assumption that your "real income" doesn't change. Realistically, your income increases over time.

According to the 10/10/4 model: "...by the time you are 65, you will need 10x your income immediately prior to retirement to retire at the level you want.."

So you need 10x your final income, not your starting or even your average income.

Let's say you're 20 and making 30k today. Your "10x" number is 300k. You save 10% for 10 years and save just over 1 year's worth of income (say 31k). At the end of 10 years you make the big switch and find a new job earning 45k (again, no inflation). Awesome for you!

However, now your "10x" number is 450k, but you only have 31k in the bank. You're behind, right? You're at year 10, you should have at least 10% of your target number, but you only have 6.8%. So what if you continue to plow along for another 10 years and then get another pay raise to 60k? Now your 10x number is at 600k, you're 20 years in to the plan but you're way behind the curve. You should have saved 120k (+ interest), but you're nowhere close to that number.

And then you have to account for medical. If you're earning 60k but receiving 10k in medical benefits (may be low-balling in the US), you now need 700k in savings (not 600k).

You can see where I'm going with this. If you follow the 10% savings route and you also follow a normal pattern of increasing income throughout your career, the 10x goal is very difficult.
- Your increasing income makes previous savings insufficient.
- High medical expenses inflate your "10x" number.
- You need consistent returns well above inflation and you need them at the right times.

Don't get me wrong, I'm a savings advocate. I save 10% and then some in tax-advantaged accounts.

But I make no pretenses of making it to 10x without saving more, getting lucky or making some savvy investments.

Again, the model presented above is very broken. Readers can follow this at their own risk.