The physical structure of urban economies - Comparative assessment

- Urban metabolism provides a characterization of material flows in urban systems.
- This paper proposes a new method for quantifying urban metabolism.
- Material flows are quantified for Lisbon, Paris, Seoul-Incheon and Shanghai.
- Most cities rely mainly on non-metallic minerals and biomass.
- Lisbon is the urban area with the least diversified manufacturing sector.

Urban metabolism provides a characterization of anthropogenic material flows in urban systems and should contribute to identify the economic activities that were involved on their supply and transformation. Typically, its quantification requires data that is not easily available in different geographies. This paper makes use of a methodology based on monetary input-output tables and international trade statistics that might be easily replicable to many metropolitan areas in the world, and which is intended to provide a first rough estimation of urban material flows.The paper discusses the results obtained for four metropolitan areas (Lisbon, Paris, Seoul-Incheon and Shanghai), assessing the material requirements of these economies. The urban areas are compared in terms of the quantity and the type of material input, destination of materials within the economy and their distribution among economic activities. The results showed that while Lisbon is the most diverse urban area in terms of the consumption of material types, it is also the urban area with the least diversified manufacturing sector.The application of this methodology to several urban areas and across multiple years enables the assessment of the technological and economic evolution of those regions.