RE: st: Defining observation specific truncation points with truncreg

[Eric Sevigny <els21+@pitt.edu>]

This was helpful. Thanks! In hindsight, the answer to my question was kind 
of intuitive. Just code the truncation value into trunc for each 
stratification of interest (in my case year). For some reason, this 
solution eluded me as I was formulating my analyses. Thanks again.

Eric

--On Thursday, September 30, 2004 10:29 PM -0500 Scott Merryman 
<smerryman@kc.rr.com> wrote:r


> Suppose, in the auto dataset, domestic observations are truncated at 17
> while foreign observations are truncated at 18. I believe you could do the
> following:
>
>
> . sysuse auto
> (1978 Automobile Data)
>
> . gen trunc = cond(foreign == 0,17, 18)
>
> . truncreg mpg price, ll(trunc) nolog
> (note: 20 obs. truncated)
>
> Truncated regression
> Limit:   lower =      trunc                             Number of obs =
> 54
>          upper =       +inf                             Wald chi2(1)  =
> 0.62
> Log likelihood = -150.79259                             Prob > chi2   =
> 0.4312
>
> -------------------------------------------------------------------------
> --- --
>          mpg |      Coef.   Std. Err.      z    P>|z|     [95% Conf.
> Interval]
> -------------+-----------------------------------------------------------
> --- --
> eq1          |
>        price |  -.0015613   .0019834    -0.79   0.431    -.0054486
> .0023261
>        _cons |    19.6171   10.84309     1.81   0.070    -1.634962
> 40.86917
> -------------+-----------------------------------------------------------
> --- --
> sigma        |
>        _cons |   9.881807   3.537671     2.79   0.005       2.9481
> 16.81551
> -------------------------------------------------------------------------
> --- --
>
> Hope this helps,
> Scott
>
> > -----Original Message-----
> > From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-
> > statalist@hsphsun2.harvard.edu] On Behalf Of Eric Sevigny
> > Sent: Thursday, September 30, 2004 5:07 PM
> > To: statalist@hsphsun2.harvard.edu
> > Subject: Re: st: Defining observation specific truncation points with
> > truncreg
> >
> > Right, but what if I have ll(10) for 1997 and ll(20) for 1996 and want to
> > model these different truncation points? Can I do that with truncreg?
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