Hello all,

I am a beginner in stata and using it for my bachelor thesis. Therefore my questions are rather basic. I hope I will still find help in this forum.

I use a regression with two fixed effects (year and company) and my data is distributed over time and firms. Now I was asked to add further independent variables and loss and big were suggested. Both are binary and indicate whether the respective firm is big (loss making). loss2 and big2 are loss(big)*timedifference:

reghdfe ln_deviation ln_timedifference loss loss2 big big2, absorb (cusip yearforecast)

Stata is omitting those variables due to collinearity. I have found the explanation online that this might be the case as the deviation of those variables over time are rather limited. Does this explanation make sense? And how can I adjust for this (exclude the variable / change the nature of this variable / do nothing)?

Furthermore, I use the two natural logarithms to make the interpretation easier. This reduces my standard error and makes some of my analysis insignificant. Is there a rule of thumb to test whether the natural logarithm fits the distribution of my data?

I am very thankful for any kind of help.