Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

RE: st: xtdpd and dgmmiv: restricting the LDV instruments


From   "Mogues, Tewodaj (IFPRI)" <T.MOGUES@CGIAR.ORG>
To   <statalist@hsphsun2.harvard.edu>
Subject   RE: st: xtdpd and dgmmiv: restricting the LDV instruments
Date   Thu, 26 Jun 2008 11:37:25 -0400

David,

Ok, this clarifies much, thanks. Just one brief final remark on using
external instruments in -xtdpdsys- : Right after my last posting, while
I was doing a few more trials on the commands to understand their
syntax, by "accident" I once included   -inst()- in xtdpdsys, and
interestingly it worked (no error message). [My initial question below
had been due to the fact that the stata manual doesn't point to -inst-
or any other option for including external instruments in -xtdpdsys-, so
I had assumed that -inst- was not an option]. Specifically, the results
for 

	xtdpdsys n w, inst(k)
and 
	xtdpd L(0/1).n w,  div(k, nodiff) div(w) dgmmiv(n) lgmmiv(n)

are identical, which suggests that -inst- in -xtdpdsys- is in fact
serving properly to accommodate external instruments. So I guess the
stata manual may have just accidentally omitted this.

Thanks for all your help.
Tewodaj 




© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index