Fig 7. Classification of Spanish cities into three categories based on the spending behavior of their residents.

Classification was performed separately for the three different city definition levels–Large Urban Zones (LUZ), Functional Urban Areas (FUA), and Conurbations (CON). Clustering into two categories can be, to large extent, recreated by merging clusters B and C into one (the consistency between the two- and three-cluster cases was quantified as high as 100% for LUZ, 98% for FUA, and 97% for CON).