I was accused of dishonesty by another poster for not having used a Baby Boomer for my Social Security calculation. So, I'm recrunching with a Baby Boomer.
I'm using a Boomer born in January 1946 (the first year of the Baby Boom), to minimize the need for guessing about the future. Our hero is 63 years old this year. He earns $50,406 (the median income for a person age 45-64). He'll retire at the start of 2012 (when he can get full benefits). I went to a life expectancy calculator, and based on him being 63, white, male, middle-class, and married, a non-smoker, with unexceptional health stats and habits, he can expect to live to around 87 (it would be shorter if he were black, longer if he were a woman, so it seemed like a fair middle-of-the-road person to use).
Based on the aforesaid assumptions, the SSA estimates he'll receive $1457 per month, starting that first month, thereafter escalated by CPI-W (inflation). Assuming CPI-W rises during his retirement at an average of 3.77% (the same average rate as during his career), and assuming there are no other unscheduled handouts to seniors, he will have taken out $583,241 from SS, in monthly benefits checks, by the time of his death. That compares to a lifetime SS contribution (his taxes plus his employers') of $137,870 (based on the SSA's own calculator's earnings estimators). So, he'll be taking out more than four times as much as he contributed.
Of course, it's not that simple, since one can rightly point out that he should get some reasonable rate of return on those contributions, as if he'd invested them. If nothing else, he should get something pegged to the federal government's "cost of money" (since the money he hands to the government in SS taxes is money the government doesn't wind up borrowing and paying interest on). But the government's cost of money is very low, since it's such a high-rated borrower. If you were planning to retire in 30 years and bought yourself a 30-year Treasury today, to pay for it, you'd only get 4.5% -- and shorter periods get you crummier rates. The 5-year is only getting you 2.375% right now. An average government IOU, right now, is probably getting around 3% (lumping together the various terms), and that just isn't going to cut it in turning $137,870 of contributions into $583,241 in benefits.
In fact, if we impose a 3% return on the calculation, the guy winds up drawing in excess of $380,000 more out of the system than he ever paid in. In order for him just to break even (drawing out exactly the real value he paid in, after accounting for interest), you'd need to assume over a 5.5% average rate of return on his contributed funds, and that's just not realistic on a safe investment subject to no tax. In the real world, you can't go out and find a near-certain 5.5% return, much less one where you wouldn't pay taxes on the interest (knocking down your effective return). So, in the real world, he's going to be drawing more value out than what he paid in was worth.
Keep in mind, that's without us even taking account of SS death benefits, administrative costs, SS disability, and intra-generation wealth shifting (subsidization of the retirements of the poor). Count those things, and you'd need a middle-of-the-road retiree to pay more into the system than he takes out just for the system to break even. Which means the system itself winds up even deeper in the hole when average retirees, in fact, take more out than they put in.
So, how is it that this Baby Boomer can pull $583,241 out of a system into which he only contributed $137,870, if only part of it is explained by the implicit rate of return his contributions received? The answer is inter-generational wealth shifting. It's not as extreme as in the early years (where the very first Social Security beneficiary pulled out almost 1000 times the value she'd paid in), but it's still there. Every generation of retirees (except that first one) has its retirements subsidized by the paychecks of the workers who came after them. That's certainly true of the "Silent Generation," and appears like it will also be the case for Baby Boomer retirees. And when an unscheduled $250 hand-out is stacked on top of the scheduled payments, this subsidization is simply increased further.