Jimmy Avila remembers weaving his way around open sewers as he made his way to school in Diadema, a town of some 400,000 people on the southern edge of São Paulo. Back in the early 1990s, Mr Avila’s rough concrete and brick home on Avenida das Nações faced rows of more ramshackle houses made from wood and corrugated iron. Dealers sold crack on street corners.

“People here had no expectations and there were really big frustrations. Most of the kids here had seen someone die and it was really difficult place for the police to enter,” says Mr Avila, 25, who works as a researcher and studies economics.