A causal metric is one used to choose a course of action that leads to improvement. It identifies a driver or reason for the observed outcome, suggests specific intervention(s) for positive change, and provides a means to assess whether the intervention has the desired effect. 
“Causal” is one of the 10 Characteristics of an Ideal Metric designated by the Marketing Accountability Standards Board.
- Accountable Marketing: Linking marketing actions to financial performance, 1st Edition; Eds. Stewart, David W. & Gugel, Craig; Routledge, 2016.
- Universal Marketing Dictionary Project, 2023.