Dear all
Now I proceed a research. The sample data I use is the financial indexes of listed firms, except for the key independent variable which is at the region-level. The dependent variable is at the level of firm. But the key independent variable we focus on is at the level of region.
Now I don't understand how to decide the fixed effect in the econometrics model. Which level fixed effect I should choose? firm or region? or both? Why? Can you recommend some relevant reference?
Best Wish
Lee Jack