Saw this news item: http://enews.earthlink.net/article/bus?guid=20140104/73236dae-a5a1-45f6-8402-8ce67279bd1d
"We all cannot believe that we have been fighting this theory for more than 150 years," said April Yanyuan Wu, a research economist at the Center for Retirement Research at Boston College, who co-authored a paper last year on the subject. (An employed academic, I might add.)
The theory Wu and other economists are fighting is known as "lump of labor," and it has maintained traction in the U.S., particularly in a climate of high unemployment. The theory dates to 1851 and says if a group enters the labor market — or in this case, remains in it beyond their normal retirement date — others will be unable to gain employment or will have their hours cut.
Still, many remain unconvinced. James Galbraith, a professor of government at the University of Texas at Austin, "I can't imagine how you could refute that. The older worker retires, the employer looks around and hires another worker," he said. "It's like refuting elementary arithmetic."
If all jobs were equal and close at hand, I'd agree with Wu... but in the real world, choices are much fewer and not always practical.