I think it's the opposite. You have some money that could be used as a bridge fund. The question is whether to take SS at 62 and invest the bridge fund, or defer to 62, and drain the bridge fund over 8 years.
The higher the return, the better you'll do if you keep the whole bridge fund invested. In other words, take SS now so you don't have to spend any of the bridge fund, and let it grow. IF you have reason to believe the return will be high.
If the return on investments were high enough, you'd never catch up by spending down that bridge fund and deferring to 70 even with the higher benefits later. The bridge fund would be large enough to continue producing more return than the higher benefits provide.
I didn't miss that. What I'm pointing out is that (I think) pb4 made the case for holding a mortgage is that you don't compare a mortgage rate to the alternative of holding a safe CD investment, you compare it to your overall investment rate. But in this situation, he is saying to use a CD rate for comparison, rather than your overall investment rate. That's inconsistent. He uses the point that people don't (usually) adjust their AA whether or not they've paid off their mortgage. One could just as easily assume that they don't adjust their AA whether they take SS at 62, 70, or somewhere in between.
If I've misspoken pb4 can correct me.