A classic trap for all of us and especially for economists and marketers.
A happens, then B ==> A causes B
This is something we all need to question from time to time. Especially if we are dealing with complex / real world/ systems such as economies and target markets.
A shelf promotion, a price increase or a new law may all be the reason for changes in market share or profits.
Hope you like the clips (embedding is disabled); they come from two of my favourite shows: The West Wing and Big Bang Theory.