...a reduction in SS pension is a very low probability event./QUOTE]
You're kidding, right? The are news stories & columns & articles all over that indicate that reduction is a high probability event.
the decision to delay is not to maximize return or break even but to minimize the risk of running out of money. That risk is real, and the value must be reflected in the choice.
Granted. And that's why you need to look at the figures and make you own assessment of your risk level.
I will point out that if a person delays to age 70, then they have enough assets that they did not need the SS money for those 8 years, and it's quite unlikely that they exhausted their own money and then need to switch to SS at 70. If you are (relatively) poor, you don't have the option of delaying, because you need the SS money as soon as you retire.
Also, nobody (voluntarily) retires at 62 unless they don't need the paycheck. Which means they have considerable assets, which means that they could easily delay receiving SS, which means that they don't need the SS benefit -- not at 62 and not at 70.
We're not really talking about a whole lot of money here, either. The average monthly benefit is about $1200. The maximum is $1900 (for age 62 start). That's for someone who has been a high earner all their life -- that is, someone who has has plenty of opportunity to accumulate a lot of money to retire on, who therefore doesn't really need the SS money.
It all gets very complicated, 'cause there are so many figures, growth, COLA, etc. to juggle. That's why I worked up that spreadsheet. The basic question I had was, "Okay, I don't need the money at 62, so how about if I take it and put in into a savings account. Then at 66 or 70 I switch gears and start spending the SS money and suppliment that with withdrawals from the savings account such that the total is equal to what the SS benefit would be if I had simply delayed collecting SS until that age." Now that I'm drawing down the account, when will it be depleted? At that point, the suppliment disappears, so all I get is what SS pays.
The question is: What is that age? At 0% interest and no SS COLA, that's about 77. That's a breakeven time of 15 years.
Each person must decide for themself whether that's acceptable or not. It's rather like an annuity, and you need to decide if you want your heirs to inherit any money if you die before you start collecting SS. Like someone said, if you delay until 70 but then die at 68, your rate of return is zero. Whereas if you start and save, they inherit the money in the account.
For some people, you can also toss in the complexity of claiming on a spouse, which is way to complex for me to figure.