I'm trying to run the PPML regression with command ppmlhdfe.
If I don't include interaction terms in my independent variables, it works. But there is a warning:
dependent variable takes very low values after standardizing (4.7715e-11)
If I include the interaction terms, as follow, I got error messages.
(dropped 16389 observations that are either singletons or separated by a fixed effe
> ct)
_assert_abort(): 3498 Invalid options: no
assert_msg(): - function returned error
GLM::init_fixed_effects(): - function returned error
<istmt>: - function returned error
r(3498);
(Note: upstreamness is not a dummy variables)
What causes the warning and error messages, your suggestion will be highly appreciated! Thanks in advance.
If I don't include interaction terms in my independent variables, it works. But there is a warning:
dependent variable takes very low values after standardizing (4.7715e-11)
Code:
ppmlhdfe flow ldist contig comlang_off own, noconstant absorb(imp#sector exp#sector) outreg2 using Result.xls, keep(ldist contig comlang_off own) dec(3)
Code:
ppmlhdfe flow ldist contig comlang_off own c.ldist#c.upstreamness c.contig#c.upstreamness c.comlang_off#c.upstreamness c.own#c.upstreamness, no constant a(imp#sector exp#sector) outreg2 using Result.xls, keep(ldist contig comlang_off own c.ldist#c.upstreamness c.contig#c.upstreamness c.comlang_off#c.upstreamness c.own#c.upstreamness) dec(3)
> ct)
_assert_abort(): 3498 Invalid options: no
assert_msg(): - function returned error
GLM::init_fixed_effects(): - function returned error
<istmt>: - function returned error
r(3498);
(Note: upstreamness is not a dummy variables)
What causes the warning and error messages, your suggestion will be highly appreciated! Thanks in advance.

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