Ambiguous Abbreviation Error with test command

[Roman Johnson]

Hi, All:

After running a logistic regression, I wanted to do a Wald test for my variable female. Stata gives me a r111 and says that the variable female is not found, but it is because I am able to tabulate it. Can someone please help me figure out why my "test" command is not working?

logit binarycitations i.female i.mmale i.nopub1 i.fellow i.workadmn

Iteration 0: log likelihood = -174.02793
Iteration 1: log likelihood = -150.89347
Iteration 2: log likelihood = -149.39611
Iteration 3: log likelihood = -149.38601
Iteration 4: log likelihood = -149.38601

Logistic regression Number of obs = 297
LR chi2(5) = 49.28
Prob > chi2 = 0.0000
Log likelihood = -149.38601 Pseudo R2 = 0.1416

-------------------------------------------------------------------------------
binarycitat~s | Coef. Std. Err. z P>|z| [95% Conf. Interval]
--------------+----------------------------------------------------------------
female |
1Female | -.7626615 .3380316 -2.26 0.024 -1.425191 -.1001317
|
mmale |
1MalMent | -.7277077 1.108126 -0.66 0.511 -2.899595 1.44418
|
nopub1 |
1NoPubs | -1.405057 .4389459 -3.20 0.001 -2.265375 -.5447388
|
fellow |
1Fellow | 1.318628 .292187 4.51 0.000 .7459525 1.891304
|
workadmn |
1Admin | .6988945 .5506152 1.27 0.204 -.3802914 1.77808
_cons | -.4831004 1.109789 -0.44 0.663 -2.658247 1.692046
-------------------------------------------------------------------------------

.
end of do-file

. do "C:\Users\rjohn123\AppData\Local\Temp\STD23a8_0000 00.tmp"

. test female
female not found
r(111);

end of do-file

r(111);

. tab female

Female? | Freq. Percent Cum.
------------+-----------------------------------
0Male | 195 65.66 65.66
1Female | 102 34.34 100.00
------------+-----------------------------------
Total | 297 100.00

[Nick Cox]

It's in the help. Once you use factor variable notation, the coefficient has to be specified differently. We can't use your data example because there isn't one, but the following shows the issue.

. sysuse auto, clear
(1978 Automobile Data)

. regress mpg foreign

      Source |       SS           df       MS      Number of obs   =        74
-------------+----------------------------------   F(1, 72)        =     13.18
       Model |  378.153515         1  378.153515   Prob > F        =    0.0005
    Residual |  2065.30594        72  28.6848048   R-squared       =    0.1548
-------------+----------------------------------   Adj R-squared   =    0.1430
       Total |  2443.45946        73  33.4720474   Root MSE        =    5.3558

------------------------------------------------------------------------------
         mpg |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
     foreign |   4.945804   1.362162     3.63   0.001     2.230384    7.661225
       _cons |   19.82692   .7427186    26.70   0.000     18.34634    21.30751
------------------------------------------------------------------------------

. test foreign

 ( 1)  foreign = 0

       F(  1,    72) =   13.18
            Prob > F =    0.0005

. regress mpg i.foreign

      Source |       SS           df       MS      Number of obs   =        74
-------------+----------------------------------   F(1, 72)        =     13.18
       Model |  378.153515         1  378.153515   Prob > F        =    0.0005
    Residual |  2065.30594        72  28.6848048   R-squared       =    0.1548
-------------+----------------------------------   Adj R-squared   =    0.1430
       Total |  2443.45946        73  33.4720474   Root MSE        =    5.3558

------------------------------------------------------------------------------
         mpg |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
     foreign |
    Foreign  |   4.945804   1.362162     3.63   0.001     2.230384    7.661225
       _cons |   19.82692   .7427186    26.70   0.000     18.34634    21.30751
------------------------------------------------------------------------------

. test foreign
foreign not found
r(111);

. test 1.foreign

 ( 1)  1.foreign = 0

       F(  1,    72) =   13.18
            Prob > F =    0.0005