Heckman selection model singular matrix
Posted: Fri Aug 24, 2018 8:38 pm
Hi there,
I have problem with near singular matrix in heckman estimation. I think I don't have dummy variable trap problem. I don't know what the problem is. Maybe anyone can help me?
I run estimation with following command:
And here the workfile attached
I have problem with near singular matrix in heckman estimation. I think I don't have dummy variable trap problem. I don't know what the problem is. Maybe anyone can help me?
I run estimation with following command:
Code: Select all
smpl if ar02b=1 and h_income<>NA
equation milk_exp.heckit(2step) exp_milk h_income head_age head_educ elder_n children_n @ buy_milk head_educ elder_n children_n free_milk