I know the general consensus is "It depends on how long you live", but here I want to make a case for early withdrawal at 62.

In constant dollar terms, starting my benefits at 62 gives me 70 cents on the dollar (compared to full benefits at 67) vs 124 cents starting at 70. The ratio is therefore, 124/70 = 1.77. That is, I receive 77% more in return for delaying my benefits until 70, at the cost of foregoing SS income for 8 years.

Suppose the amount I receive starting at 62 is X, the amount I would receive if I start at 70 is then 1.77X. The break even comes at ~ age 80: 18 years * X = 18X, 10 years * 1.77X = 17.7X. Age 80 is 18 years after age 62, and 10 years after age 70. Life expectancy is 79 years, so there's roughly 50% chance one will live long enough to reap the benefits of starting late.

But what if we invest the benefits starting at 62? By age 80 I'll have invested 8X. Assuming an average real annual return of 5%, my 8X will have compounded to ~10X.

Starting at 70, to enjoy the good life and keep pace with the late withdrawal case, I stop investing and instead spend 1.77X each year, just like I would if I were to withdraw late. 1X of my spending comes from my annual benefits, the remaining 0.77X from my invested pile that has grown to 10X by now. Whatever is not withdrawn is left invested in the market.

0.77X out of 10X is 7.7%, so essentially I'm doing a 7.7% rule on the invested benefits starting at 70.

Running the simulation on cfiresim.com with 100% equity and 7.7% spending, there's a 92% chance my investments will last at least 10 years (age 80), 71% chance for 15 years (age 85), and 57% chance for 20 years (age 90), hence pushing up the break even age albeit with lower and lower probabilities.

Only 35% of people live past their 90th birthday. So the chance of one living long enough AND having the break even point that high is 35% x (1 - 57%) = 16.5%.

This seems to suggest that withdrawing early at 62 makes sense for most people. Am I missing anything? Thoughts?