Dear Statalist,

I am trying to do a piecewice regression with panel data, using nl to find the correct "break point", and xtreg on the "step 2" regression.
- Does anyone know if there are problems using these functions that I should be aware of?
- I have tried to run the xtreg without a constant, but stata says "option noconstant not allowed". Is it not possible to run a xtreg without a constant?