Mr Sudhir, a Delhi market trader who sold Richard Sennett a hot mobile phone, is one of the unlikely heroes of Building and Dwelling, his latest magnum opus on living in the contemporary city. The two men – both grandparents, as they discovered – struck up a rapport when a furious Sennett tried to return the dud phone and was disarmed by the framed photos of Sudhir’s grandchildren perched on cardboard boxes of other stolen mobiles. With its overflowing vitality, Nehru Place, the street market on top of a car park where Sudhir plies his trade, is one of the numerous places of spontaneous exchange between strangers which flourish in the informal economy and which, to the surprise of many planners, often form a city’s most attractive and successful spaces.

Sennett describes Nehru Place as a cité, a term he contrasts with ville, which is defined as the overall infrastructure of the city. The cité is a particular place with strong local characteristics and a sense of identity, a consciousness even – and here Sennett echoes Jane Jacobs’s