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Re: st: _rmcoll issues
From
Stas Kolenikov <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: _rmcoll issues
Date
Tue, 10 Dec 2013 22:43:50 -0500
That's still not the right answer to the problem. I ended up creating
the interaction of the two with seven levels, and using that in the
regression, although I would rather have the main effects.
-- Stas Kolenikov, PhD, PStat (ASA, SSC)
-- Senior Survey Statistician, Abt SRBI
-- Opinions stated in this email are mine only, and do not reflect the
position of my employer
-- http://stas.kolenikov.name
On Tue, Dec 10, 2013 at 10:39 PM, Richard Williams
<[email protected]> wrote:
> At 05:31 PM 12/10/2013, Stas Kolenikov wrote:
>>
>> I have the following cross-tab of two variables:
>>
>> . tab pd2usmex years_in_us
>>
>> PD2. What |
>> country |
>> were you | years_in_us
>> born in? | 1 2 3 4 | Total
>> -----------+--------------------------------------------+----------
>> 1 | 240 0 0 0 | 240
>> 2 | 0 103 451 378 | 932
>> 9 | 0 33 99 123 | 255
>> -----------+--------------------------------------------+----------
>> Total | 240 136 550 501 | 1,427
>>
>> For whatever reason, _rmcoll senses that something is fishy between
>> the two variables, but decides to drop the last category of the second
>> variable, rather than the first one on which these two variables
>> logically overlap.
>>
>> . _rmcoll ib1.pd2usmex ib1.years_in_us
>> note: 4.years_in_us omitted because of collinearity
>>
>> I think this is a bit odd.
>
>
> I think it just goes with the highest code. Try running this (drop the fws
> if you don't need them):
>
> preserve
> recode years_in_us (3 = 5)
> _rmcoll ib1.pd2usmex ib1.years_in_us [fw = freq]
> recode years_in_us (2 = 6)
> _rmcoll ib1.pd2usmex ib1.years_in_us [fw = freq]
> restore
> preserve
> recode years_in_us (1 = 5)
> recode years_in_us (2 = 1)
> _rmcoll ib1.pd2usmex ib1.years_in_us [fw = freq]
> restore
>
> The highest value always gets dropped.
>
>
>
>> -- Stas Kolenikov, PhD, PStat (ASA, SSC)
>> -- Senior Survey Statistician, Abt SRBI
>> -- Opinions stated in this email are mine only, and do not reflect the
>> position of my employer
>> -- http://stas.kolenikov.name
>> *
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>
>
> -------------------------------------------
> Richard Williams, Notre Dame Dept of Sociology
> OFFICE: (574)631-6668, (574)631-6463
> HOME: (574)289-5227
> EMAIL: [email protected]
> WWW: http://www.nd.edu/~rwilliam
>
>
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