Hello,
I have a little question. I am analyzing a simple fixed effects model. I have my firms classified by class (so each class is an individual id) and I have interactions between my independent variable (the exchange rate) and the dummy associated to the class. Basically I want to study how the same appreciation of the exchange rate affects the performance of the different classes. I observed that if I run my regression without interaction terms, I get reasonable results. If I run the regression without fe and only with interaction terms and I get beautiful results, super intuitive. My question is: is there a rigorous way to check which specification is more correct? I am sorry for the stupid question, I typically do theoretical models :-)
Many thanks,

ISabella