The unemployment rate continues to hover around historic lows — 3.9 percent as of last month. The tight labor market has been good news for groups that often have a harder time finding jobs, like people 55 and older. Unemployment for them is even lower at 3.1 percent. The number of older Americans in the workforce has been on the rise, and economists have lots of theories why — fewer pensions, changes in Social Security and 401(k)s, or this one: being broke and needing to work. And though more older people are working, some researchers have found that half the jobs they take are low-wage, temporary or gig work. 

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