The dynamics of public safety in cities: A case study of Shanghai from 2010 to 2025

•We studied Shanghai's urban public safety dynamics.•Urban public safety is composed of development, livability, crime and disaster.•A grey theory coupled system dynamic model applied to simulate public safety.•Shanghai might enjoy increasing public safety for the next 15 years.•Public safety in Shanghai can be disturbed rather easily by unforeseeable events.

Cities in China are facing increasing challenges. Urban public safety concerns including urban crime, urban livability and urban disasters start to attract governmental, academic as well as public attention. Applying a system dynamics modeling scheme, this research investigates and attempts to simulate the public safety dynamics of Shanghai with a set of collected indicators that describes Shanghai's infrastructure and development, population, crime, livability and disaster during the past decade (2000-2009). The feedback loops are constructed based on exploratory data mining through regular statistical analyses and grey system simulation. The analytical results suggest Shanghai's public safety is increasing due to a high level of urban socioeconomic development, which provides a foundation for urban public safety. In the meantime, factors that 'expend' such foundation (crimes and disasters) increased at a relatively lower level. Dynamic simulation on Shanghai's public safety suggests that the city could still enjoy its continuous improvement of public safety providing the city continues to develop like in the past decade, which might not be the case in the long run. A few scenarios are presented by altering a few critical variables to demonstrate potential public safety dynamics of Shanghai in the next 15 years.