Re: st: setting cross-group constraints using gologit2

 From Richard Williams To statalist@hsphsun2.harvard.edu Subject Re: st: setting cross-group constraints using gologit2 Date Thu, 17 May 2007 21:54:18 -0500

```At 12:03 PM 5/17/2007, William Magee wrote:
```
```Dear Statalist Members,

I am trying to set constraints on cutpoints in gologit2
(whether that is a good idea or not is also a question)
```
I'm not sure why you would want to do that, or how you would decide what the constraints should be, but it is possible. As noted in the gologit2 help file, "When using the constraint command, it is usually easiest and safest to refer to equations by their equation #, e.g. #1, #2, etc." Ergo,

. use "http://www.indiana.edu/~jslsoc/stata/spex_data/ordwarm2.dta";
(77 & 89 General Social Survey)

. constraint 1 [#1]_cons = 2
. constraint 2 [#2]_cons = .5
. constraint 3 [#3]_cons = -1
. gologit2 warm yr89 male white, cons(1-3)

Generalized Ordered Logit Estimates Number of obs = 2293
Wald chi2(9) = 245.40
Prob > chi2 = 0.0000
Log likelihood = -2907.343 Pseudo R2 = 0.0295

( 1) [1SD]_cons = 2
( 2) [2D]_cons = .5
( 3) [3A]_cons = -1
------------------------------------------------------------------------------
warm | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
1SD |
yr89 | 1.068941 .1484313 7.20 0.000 .7780213 1.359861
male | -.2354959 .1186701 -1.98 0.047 -.4680849 -.0029068
white | -.3554515 .0957235 -3.71 0.000 -.5430661 -.167837
_cons | 2 . . . . .
-------------+----------------------------------------------------------------
2D |
yr89 | .6031904 .0857522 7.03 0.000 .4351192 .7712616
male | -.57481 .0821098 -7.00 0.000 -.7357422 -.4138779
white | -.2764247 .0674725 -4.10 0.000 -.4086685 -.144181
_cons | .5 . . . . .
-------------+----------------------------------------------------------------
3A |
yr89 | .3915407 .1036324 3.78 0.000 .1884249 .5946565
male | -.996458 .1176216 -8.47 0.000 -1.226992 -.7659239
white | -.3369808 .0834112 -4.04 0.000 -.5004638 -.1734977
_cons | -1 . . . . .
------------------------------------------------------------------------------

This will also work - don't ask why, it just does :)

. constraint 1 [eq1]_cons = 2
. constraint 2 [eq2]_cons = .5
. constraint 3 [eq3]_cons = -1
. gologit2 warm yr89 male white, cons(1-3)
[same output as above]

-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
OFFICE: (574)631-6668, (574)631-6463
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EMAIL: Richard.A.Williams.5@ND.Edu
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