EKC on STATA

[Andrea Abbate]

Hello,
I am comparing a linear, quadratic and cubic regression results of a Panel dataset.
Those are my commands used in stata:

- xtreg WFprod GDPpc POPden FREE STRESS AGRIland, fe
- xtreg WFprod GDPpc GDPpcq POPden FREE STRESS AGRIland, fe
- xtreg WFprod GDPpc GDPpcq GDPpcC POPden FREE STRESS AGRIland, fe

Now, I would like to see on different scatter plots with x=GDPpc and Y=WFprod how does it fit my regression curve (linear, quadratic and then cubic),
and if it possible, to see the quadratic and cubic turning points.
Can somebody help me with the code, please?
Thanks

[Carlo Lazzaro]

Andrea:
welcome to this forum.
Creating >2 order polynomials terms by hand is not rewarding at all, especially for what you'after.
I would consider -help fvvarlist- on creating categorical variables and interactions in a way that is familiar for -margins- and -marginsplot-, two wonderful commands for getting the most out of your regression models.