Sales fell. Proving what caused it is the whole job.
You are the testifying economist. The other side has one too.
Northgate Retail is suing over a pricing policy it says destroyed its sales. Sales did fall. The entire case is whether the policy caused the fall - and how much of it.
DiDdifference the differences
PARALLEL TRENDSthe assumption that can break
CONFOUNDERSwhat else moved
DAMAGESthe number you defend
Interview lens: consulting cases are won on the alternative explanation you find before opposing counsel does. Anyone can subtract two numbers.