Marketers have long investigated what motivates us to buy stuff: how to arrange shopping aisles and shelves; the best colors, fonts, and logos to use on packaging; and so on. But, until recently, little work has gone into the other end of a product's life: why and when we recycle. How come some of us do it and some of us don't, and how come sometimes we forget or pretend it doesn't matter, even when we know we should?

Remi Trudel, an assistant professor at Boston University, has begun to answer these questions in a series of experiments looking at our recycling ticks and foibles. For example, he's found that we're twice as likely to recycle when the item is relatively intact, compared to when it's torn or crumpled. We're more likely to recycle when we identify and like a brand—whether it's a Coke, or a sweatshirt from college. And, we're more likely to waste resources, perversely, when we know what we don't use will be recycled. Recycling, in that sense, promotes consumption, as it frees us from the guilt of using more than we might, he says.