Hi all:
I use two methods to control for fixed effects: (1) use dummy variables, (2) demean all the variables.
Results turn out to be highly close, but not identical. The difference is no more than 0.000001。
In theory, they should be identical. How to explain the trivial differences?
(I guess it is related to my huge sample size. When I try both methods with a very small dataset, there is no such difference.)
Many thanks!
GBL
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