The role of risk measures in relating earthquake risks at building and portfolio levels

The potentially large spatial footprint of earthquake disasters and the increased concentration population values in dense urban areas call for an explicit consideration seismic risk at a regional, building portfolio level. relation between building-level portfolio-level is helpful if one wants to meet specific regional tolerance level by specifying targets individual buildings. We examine four types common measures point importance subadditivity, measure mathematical property, deriving conservative upper-bound building-specific risks. Subadditive measures, such as Expected Shortfall, allow estimates upper bounds risk. In case study, we show that nonsubadditive commonly used engineering can lead counter-intuitive nonconservative perceptions risk, especially when extrapolates from buildings entire portfolio. also illustrate advantages subadditive assessment.