>"Let's ignore the interaction term for the sake of simplicity. It doesn't change anything in what follows." It changes the estimates if you don't assume the i

>"Let's ignore the interaction term for the sake of simplicity. It doesn't change anything in what follows." It changes the estimates if you don't assume the interaction coefficient = 0, how can you just ignore it? Actually, not assuming zero interaction changes everything: https://en.wikipedia.org/wiki/Principle_of_marginality https://en.wikipedia.org/wiki/Principle_of_marginality