The optimal sifting of waste

The economics of recycling is explained in this recent Economist article. India, it appears, does a great job recycling. This is because the sorting of trash, something you might have never thought about, is done extremely well. India's poor do it and they have a financial incentive -- however small that might be -- to do it well. One example from Bombay, below, of meticulous, nuanced sorting:

The swarming flies and sickly, fetid smell that fill the shed do not seem to put her off her [Mrs.Hiyale's] work. She sits on a low, pink plastic stool, behind a mound of unsorted goods which she is gradually dividing into smaller piles. Copper wiring goes in one heap, aluminium foil in another. Iron and steel is divided by thickness; the heftier pieces fetch a higher price. The same goes for plastic bags. Cloth, leather, Tetra Paks—each has its own pile. Coconut shells go into a bag hanging from the rafters.

Another woman comes in, carrying a load of plastic bottles several times her own size on her head. She will sort it by type of plastic and by colour. In another part of the shed a third woman stands knee-deep in waste paper which she is separating into cardboard, newspaper, office paper, glossy paper, coloured paper and envelopes—which, she says proudly, fetch four rupees a kilo, against just one rupee for the newspaper. [Link]

In general, "the narrower the categories into which recyclables are sorted, and the more meticulous the separation, the easier they are to process, and the higher the price they fetch." Rich countries, with their mechanized equipment designed to sift and sort, may not be as effective; machines may be more error prone and are not yet capable of recognizing nuanced categories. But rich countries can't have people in their own countries do it manually -- as happens in India -- because it is too expensive.

For more such insights, read the full piece.