st: comparing coefficients after treatreg

[Agnieszka Kanas <a.kanas@maw.ru.nl>]

Dear Statalisters,


I have a question how to compare the coefficients between two models 
after treatreg. I used suest and then test commands. However, after 
running a test command I get an error message "equation not found." I 
think the problem might be that I have a multiple-estimation equation. 
Also, is it possible to compare treatment effect coefficients between 
two models?

I post my code here; any suggestion is greatly appreciated.


*-------------begin example--------------------

#del ;



treatreg ww wa cit, treat(wc=wmed wfed);

estimates store M1;

treatreg ww wa cit health, treat(wc=wmed wfed);

estimates store M2;

#del cr

est dir

suest M1 M2

vce, block format(%7.3f) rho

test [M1_mean]wa = [M2_mean]wa
*to compare treatment effect coefficients
test [M1_mean]wc = [M2_mean]wc


*-------------------------end example-----------------------
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