Re: st: summing across bins

[Richard Williams <Richard.A.Williams.5@ND.edu>]

At 08:30 AM 2/13/2006, Lenna Nepomnyaschy wrote:
> Hi,
>
> I just downloaded the ado file binsm, which allows you to graph mean 
> values (or other values) of yvar on bins of xvar.  But, I need to 
> use weights. Does anyone have another way to do this that allow 
> weights?  the binsm command does not.
>
> Alternatively, does anyone know how to create a variable with 
> weighted means across various groups. the command
>
> egen newvar=mean(oldvar), by(group)
> does not allow weights.
There may be a more straightforward way - but if you have Stata 9 you 
can use the -mean- command.

. webuse nhanes2f

. mean age [pw=finalwgt], over(race)

Mean estimation                     Number of obs    =   10337

        White: race = White
        Black: race = Black
        Other: race = Other

--------------------------------------------------------------
        Over |       Mean   Std. Err.     [95% Conf. Interval]
-------------+------------------------------------------------
age          |
       White |   42.50856    .172878      42.16968    42.84743
       Black |   40.21349   .5020604      39.22935    41.19762
       Other |   40.46675   1.066255      38.37669    42.55682
--------------------------------------------------------------

. mat b = e(b)

. gen newvar = b[1,1] if race==1
(1286 missing values generated)

. replace newvar = b[1,2] if race==2
(1086 real changes made)

. replace newvar = b[1,3] if race==3
(200 real changes made)

. mean newvar, over(race)

Mean estimation                     Number of obs    =   10337

        White: race = White
        Black: race = Black
        Other: race = Other

--------------------------------------------------------------
        Over |       Mean   Std. Err.     [95% Conf. Interval]
-------------+------------------------------------------------
newvar       |
       White |   42.50856          0             .           .
       Black |   40.21349          0             .           .
       Other |   40.46675          0             .           .
--------------------------------------------------------------



-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
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