Giving Compass' Take:

• RAND's American Working Conditions Survey revealed a trend called "unretirement," meaning that the elderly respondents said that they would return to the workforce for the right opportunity. 

• The author notes that when the elderly participate in the workforce, it helps to offset the decline in the labor force participation rate. How can employers help to keep the "unretirement" trend going?

• Here is a comprehensive guide to funding in aging. 

Ahhhhh, retirement. For many, the word conjures up images of leisurely lunches and finally picking up those books you've been meaning to read. But a majority of retirees say they would return to work—and many already have, according to RAND's American Working Conditions Survey. Welcome to the trend of “unretirement.”

More than half of retirees 50 and older said they would work in the future for the right opportunity, the survey found — and the percentage is even higher among the college-educated. Meanwhile, 39 percent of workers 65 and older who are currently employed had previously retired at some point.

“What we found is consistent with retirement being a fluid concept,” according to Kathleen Mullen, a senior economist at RAND and coauthor of a recent report on the subject. “Significant numbers of older people move in and out of the workforce. Retirement isn't necessarily permanent.”

In fact, older people are the fastest-growing segment of the U.S. workforce. One in five workers today is 55 or older; by 2024, that number will be one in four, according to the Bureau of Labor Statistics (BLS). Much of this shift is due to the behavior of the nation's two largest populations: Baby boomers are delaying retirement, and millennials are entering the workforce later.

Many experts say that older workers staying on the job longer is helping to offset the decline in the labor force participation rate. The rate is expected to drop from 62.9 percent in 2014 to 60.9 percent in 2024—the lowest level since the early 1970s — which the BLS predicts will likely keep a lid on economic growth.

Read the full article about why unretirement is working for older Americans by Melissa Bauman at rand.org.