If you’ve ever bought something at a yard sale or a flea market, if you’ve ever left a piece of furniture or some other item out on the sidewalk for someone else to take and use, you’ve taken part in the reuse economy. And it’s a bigger part of the overall Maine economy than you might imagine. Cindy Isenhour, associate professor of anthropology who also works with the Climate Change Institute and the Senator George J. Mitchell Center, has studied this topic for several years now — why the reuse economy is so robust in Maine and where this trend is going