Hey @cetagostini, thanks! I’ve seen it, but I’m still unsure. My situation is a bit different since it’s inverse- I’ve lowered the budget. So I’m not sure if x and Δx should be for the entire market or just the test market.
The counterfactual thinking behind geo tests is that we created a test group where the budget was reduced to $0, and a comparable control group where the budget remained at $1700 (their pre-test allocation). So the difference in treatment between test and control is $1700, and it resulted in a -400 change in y.
I feel like I need to incorporate that somehow into the model. What do you think? Can you help me understand what to input into the model?
Thanks! BTW- your webinar on MMM was incredibly interesting and insightful, thanks for that!