According to urban experts, squatters are now the dominant city builders in the world. Over time the tarpaper shacks are rebuilt of masonry, four and five stories high. The homes eventually have refrigerators, TVs, washing machines, and computers. Motor scooters multiply. Air conditioners require new levels of electricity.

Meanwhile the marginal-land subsistence farms the squatters abandoned are growing back—the trees and shrubs no longer cleared for crops or burned for cooking, the wildlife no longer eaten. According to a 2005 UN report, fifty-five times more rainforest is growing back as second growth in the newly empty rural areas than is being cut down from primary forest. In town, the squatters are the world’s most efficient users of energy and materials. They recycle everything themselves, and provide extensive recycling services for the city at large. Dharavi, the biggest slum in Mumbai, has four thousand recycling units and thirty thousand ragpickers.