On the other hand, the entire scenario ignores that could have been earned on the almost $200k left in the portfolio in scenario 1.
In fairness, the setup did explain that inflation and earnings would be ignored for simplicity. But let's understand how limited that growth will be. Fundamentally, portfolio growth is determined, over time, by the amount of volatility ("risk") that is taken, as we see every day. Yes, there's very little "free lunch"). Let's say that the ultimate age 70 SS deferred benefit ($34,092 per year) represents "must have" money for both Mr 63 and Mr 70. Mr 63 takes his SS at 63 and so his SS for the year only amounts to $19,476, so he needs to get the remaining $14,616 from his portfolio every year to meet his basic needs. Will he be taking a lot of risk with that money if he absolutely needs to use it (gains and principal) to meet his needs in the short term? Probably not. He won't be making a bet on startup companies. So, with that low risk, how much gain will there be? Probably little. In practice,
both Mr 63 and Mr 70 will likely have their "got to have" money in a CD ladder. Mr 63 needs to start with $116,928 [$14,616 x 8], Mr 70 needs to start with $272,736 [$34,092 x 8]). CD's have historically returned about 2% above inflation. In fact, because CDs have historically produced a little bit of real return, Mr 70 will get more extra growth to spend because he'll have more in these CDs than Mr 63 does. If CD's don't match inflation, they seldom lag it by more than 1-2% for long, so it won't be a major risk for either case.
Also, there is the issue of how much flexibility is lost by draining the portfolio as much as in Scenario 2. Maybe you feel OK with having a $495k portfolio at age 70 instead of a $680k portfolio.
I do see and agree with this concern. Mr 63 will have more of a "pot" at first, and more flexibility to accelerate spending if needed.
At age 70, both Mr 70 and Mr 63 have exhausted their CD ladders. The difference in their portfolio values is $155,808 (the difference in the amount they contributed to their CD ladders) plus any growth on that money--let's say it is now $250K. Mr 70's SS check has started coming, it meets his basic spending needs. Mr 63 gets $14,616 less from SS, and has to make up the money using the retained portfolio amount. How much flexibility does he really have with that money? Especially as he is now "short" $14,616 in real needed spending every year for as long as he lives, which on average will be 14 years (16 years for females). That's the average, he probably needs to plan for longer. Without any real growth (again, how much risk can he take with this "must have" money), his $250K stash will last 17 years. So, he doesn't have a lot of spending flexibility with this money. To the degree that Mr 70 has his basic spending "set" for life (due to the higher SS check), a case can be made that Mr 70 has
more flexibility with any savings he does have left in his portfolio. This is the case for most people reading this board--they have money beyond the minimum they need to survive. The higher guaranteed lifetime SS payment gives them more flexibility with their remaining stash (to spend it or invest with greater risk/reward). And MR 70 has had the flexibility for years
before age 70, because he knew he'd have his basic needs covered from there on out, as long as he lives. Mr 63 doesn't.
At age 63-70, both Mr 70 and Mr 63 would be dependent on SS for a large portion of their basic needs, but more-so for Mr 70. To my way of thinking that's the most significant objection to delaying SS.