The finer grouping layer beneath this atlas's driver type categories, fifty two live entities strong as of this wave: twenty groupings under Concepts by JEL top-level classification, thirteen currently populated under Economists by the same JEL scheme applied to primary field of contribution, ten under Institutions by functional role, and nine under Economic Indicators by measurement domain. Schools of Thought and Events are deliberately left flat rather than subdivided, the first because it is this atlas's own organizing spine rather than a subject to classify, the second because this field's live causation disputes resist a forced crisis typology. A subcategory exists so a category holding dozens or hundreds of entities can still be browsed as a set of human sized groups rather than one long flat list, and each carries its own prose explaining what belongs in it and what does not.