Sharing Cities Shaping Cities
In recent years, ‘sharing cities’ has spread globally, starting in 2012 when Seoul declared its intent to pursue sharing economy strategies . Other cities then followed, including Amsterdam, Boulder, and Rio de Janeiro. Their pursuits to become sharing cities also intended to face major contemporary urban challenges, including global urbanization  and resource depletion . Sharing cities make use of (often smart) technologies to connect a larger number of users to idling assets, hence to be ‘shared’ by a wider population, rather than being individually owned. Within this trend, assets that are typically shared include vehicles and rides, bedrooms and accommodation, as well as tools and competences. Environmental, social and business advantages are envisaged by many [4–6], often leading to significant financial investments by industries, public bodies and international organizations. Sharing cities is a locution which has emerged to express the marriage of the sharing economy in urban areas [7–9]. Davidson and Infranca  describe urban conditions as fundamental for the value proposition of the innovative elements of the current sharing hype. The physical and social configuration of a city shapes the way in which sharing takes place: size and type of fabric, mobility and accessibility, availability of public spaces, social norms, habits and traditions and, therefore, the unit of analysis. Vice versa, how sharing shapes—rather than being shaped by—urban features may apply likewise and, in our view, deserves attention to reflect upon the changes that the contemporary sharing-based practices may bring about.