The Brookings Institute has a really interesting study on the changing demographics of the US workforce. Highly educated people are working into their 70's now, because they are doing work they enjoy, rather than just hitting 60 and retiring... while the less educated are retiring as soon as they can, and therefore getting less Social Security, for longer...
It's a complex issue, and this article is pretty dense, but a worthwhile read.
This is also a serious issue that I have with people who want to increase the retirement age. It is one thing to allow/make lawyers and doctors and teachers work into their 70's, but blue collar people like my dad and uncles trade their health and physical well being for a wage. Making a welder work into his late 60's when he has a life expectancy of 70 because someone who works in an office will retire at 62 and live to 100 seems wrong to me.
I work an office job, I have retirement savings and am looking forward to early retirement where I live off my savings until 65 1/2 then fall back on Social Security as much as possible. The thing is that men in my family either drop dead at 65 (good for the taxpayer) or live close to 100 (Good for me). So, to be a bit morbid, I am either going to be a part of the solution or a living example of the problem.