Reader mail ...
You've mentioned Social security as insurance, previously, but I think the point deserves more emphasis. Reducing social security benefits and replacing (some of) the lost benefits with private investment accounts is still gambling EVEN if the accounts earn a relatively optimistic rate of return, and EVEN if the accounts are limited to conservative investment options. The reason why private investment accounts are RISKY is because people don't know how long they will live. Someone living to (say) 95 is going to do much worse with private investments, simply because the privately invested money is going to run out well before they die.
The scam here (on the part of those trying to sell private investment accounts as a substitute) is that they (implicitly) are talking about what someone who lives to the AVERAGE lifespan will be getting. But half (or so) of retirees are going to live LONGER than average. This half will either have to withdraw money more slowly (live less well) [and how will they be able to predict this?] or will exhaust their private investment accounts long before they die.
So with private accounts, those who die early end up with some (or much) of their money going to the heirs, and those who die late end up (potentially) in poverty. Only the hypothetical "average" person (the one who dies at an average age, having exactly exhausted his/her private investments at exactly the right time) is going to do as well as any "predicted" outcome for private investment accounts<$NoAd$>.