Older women can sometimes feel like they’re invisible to workplaces and businesses, but they're actually the trailblazers others should be watching, says Joseph F. Coughlin, director of the AgeLab at the Massachusetts Institute of Technology and author of the new book, “The Longevity Economy: Unlocking the World’s Fastest-Growing, Most Misunderstood Market.” As people get older, the future is female, he argues, with women better prepared for life after middle age than their male peers.