st: comparing regression coefficients across models

["Narasimhan Sowmyanarayanan" <narasimhan.sowmyanarayanan@gmail.com>]

Dear Statalist.

I have two models say y1 = a + bx1+cx2+e and y2 = a2 + (b1)x3+(c1)
x4+e. I want to compare if b1 = b after running the respective
regressions. I tried to store the estimates and use "test [equation1
name] _b[coefficientname] = [equation2 name] _b[coefficientname]".

I guess that stata stores only the last estimates. also when I use the
above command I get  a error

=exp required
r(100);

I am not sure what I am doing wrong. Would be grateful for pointers.

Thanks.
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