Retirement experts often recommend working longer as a way to make savings outlive the saver, but it isn't always easy.
Burnout, age discrimination, health issues and new technologies that eliminate jobs or make veteran workers' skills outdated conspire against those who try.
There is a growing wave of hope, however, that saving the world — or at least taking a shot at making it a better place — may be the answer.
"Are people working well into their retirement years because they want to or need to? I think it's both," said Chris Farrell, senior economics commentator for American Public Media radio and author of "Purpose and a Paycheck: Finding Meaning, Money and Happiness in the Second Half of Life." "They don't necessarily want to do the same thing they've been doing for 30 years, but they do want to do something they believe in."
Farrell's new book highlights several late-career changers who were motivated by some notion of finding a new value, or purpose, to their work. That didn't necessarily mean jobs in the nonprofit sector.
Often, they were entrepreneurial. The trick is finding work that engages the brain or the heart in some fundamental way, and often that means doing some good as we do well, he said.
Another recent book by Encore.org President Marc Freedman, "How to Live Forever: The Enduring Power of Connecting the Generations," calls on the 50-plus demographic to connect with younger generations, or as the Greek proverb says to "plant trees under whose shade they will never sit."
Meanwhile, several university-based programs are creating learning communities for late-career professionals transitioning to new ventures, paid or unpaid.