Useless variable decomposition

by Alexei Andreev Apr 2 2015 updated Dec 16 2015

A variable decomposition can be true but useless if it is a poor guide to intervention due to automatic links between variables, and if interventions corresponding to identical calculated quantities of one variable have different meanings and effects upon the system. Examples: Calories-In-Calories-Out in nutrition, NGDP = Consumption + Investment in economics