Re: st: RE: pooled ols interpretation, thanks

["Michael Blasnik" <michael.blasnik@verizon.net>]

Here is your last sentence:

Without knowing the constant, you could say that an increase in 1 year of 
education in 1991 results in a (0.12+0.08 = 0.20) 20% increase in family 
income.

You have added together the coefficients for a year dummy and education and 
claimed that this is the marginal effect of a year of education.  That is 
incorrect.  If you are saying that is the impact of a year of education plus 
the impact of the year being 1991 rather than the omitted reference year, 
then you are correct, but that is not how I read that statement (and what 
would the constant have to do with any of this anyway?).

Michael Blasnik


----- Original Message ----- 
From: "White, Justin" <JWhite@yesvirginia.org>
To: <statalist@hsphsun2.harvard.edu>
Sent: Friday, January 19, 2007 2:06 PM
Subject: RE: st: RE: pooled ols interpretation, thanks



> >You are confusing the point estimate and the marginal effect.
>
> I don't believe I am made a mistake.  I stated in my message that "The
> years only come into play if you wanted to calculate a point estimate
> for the growth in family income"
>
>
>
> Justin White
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu
> [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Michael
> Blasnik
> Sent: Friday, January 19, 2007 1:59 PM
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st: RE: pooled ols interpretation, thanks
>
> This is incorrect.  The marginal effect of education would still be
> estimated as the coefficient on education regardless of the values of
> the
> other variables (there are no interaction terms).  You are confusing the
>
> point estimate and the marginal effect.
>
> Please refrain from posting if you aren't fairly certain of your answer.
> I
> also think the list may be indulging too much in answering very
> elementary
> statistics questions which have nothing to do with Stata directly and
> can be
> answered through many other available resources other than Statalist.
>
> Michael Blasnik
>
>
> ----- Original Message ----- 
> From: "White, Justin" <JWhite@yesvirginia.org>
> To: <statalist@hsphsun2.harvard.edu>
> Sent: Friday, January 19, 2007 1:27 PM
> Subject: RE: st: RE: pooled ols interpretation, thanks
>
>
>
> > Take the estimated coefficients for education, d91, and the constant
> and
> > add them together.  You can do this b/c all of you independent
> variables
> > are regressed in levels.  Without knowing the constant, you could say
> > that an increase in 1 year of education in 1991 results in a
> (0.12+0.08
> > = 0.20) 20% increase in family income.
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