Well, one of them is at the top of this thresd - and I don’t say that to bash Jim, only to illustrate that it is what most people think.
If you were invested in the market as opposed to investing in SS you would be far better off, whether it is 7,8,9 or 10%. Analysts will differ in the methodology used to produce these numbers. Unless we are discussing solely index funds the percentage gains are not worthwhile in any case.
That is why I prefer fixed-rate guaranteed annuities at 80% investment and then use 20% of my contribution on a somewhat higher risk investment with a better possibility of a higher return. The market has been good to me but paramount in this is the flexibility to get in and out and change course at my discretion.
Better minds than mine can argue the average yearly percent increase in the various indexes but I trend towards the conservative number. I think Jim’s larger point is that SS is a huge wealth distribution blackhole that many a hard-working American has poured money into that they will never see. The Government will always mismanage funds of this volume. They make their decisions based on pandering for votes. When we make the decisions, we aren’t subject to any such temptations or constraints. Pardon my TMI. :)