In fact, the blue — or any color — plastic bag you put out on the curb gums up the machines at the sorting facility. Because the city doesn’t require residents to sort recyclables, it means they pay someone else to do so, increasing costs and decreasing the value of the recycling effort. A portion of what you put in the bag ends up in a landfill, on a boat to China, or sitting in a warehouse waiting for prices to improve. And city officials can’t say exactly how much of what’s collected is actually recycled, or where the recycling goes after city trucks drop it off. Despite the good intentions of household recyclers, several waste experts and recycling industry workers say the city’s program — and American recycling in general — is broken.