The aim of his study, produced in collaboration with the Paris Urbanism Agency (APUR), is to document and analyse ten kinds of circular economies which have an impact on city development. Each initiative was examined systematically looking in particular detail at the context in which it was created, the way it works technically, its level of integration in the urban environment as well as how it could be replicated in the Parisian environment. The initiatives were surveyed and identified in Mexico City, Rio, Dakar and Bangalore and selected for their positive environmental impact and maturity.