re: AW: st: PSMATCH with 2 conditions

["Caskey, Judson" <judson.caskey@anderson.ucla.edu>]

Mihai,

I was unable to replicate the problem. Can you try replicating it on one of the public datasets and send an example?

Here is what I tried:

webuse nlswork
logit union collgrad age tenure not_smsa c_city south nev_mar
predict pscore if e(sample), pr
gen pscore2=year*10+pscore 
gen pscore3=year*1000+pscore
psmatch2 union, pscore(pscore2) outcome(ln_wage) caliper(0.5) 
psmatch2 union, pscore(pscore3) outcome(ln_wage) caliper(0.5)


I get the same results in both of the psmatch2 calls. The issue may be with the bootstrapping procedure rather than with the call to psmatch2, itself.

Regards,

Judson

----------------------------------

Hi Judson,

thanks for the great tip & sorry for the late reply but I've been pretty
busy lately.

One thing though:
My industry is only 2 digit, so if I only want to match by industry, I just
multiply industry by 10 and then add the pscore, as follows:
gen pscore2=3-digit-industry*10+pscore
And then psmatch2 as indicated by you in the link.
THE PROBLEM occurred when I used 1000 instead of 10, and then 100000 instead
of 1000; ALL 3 yielded different results (T & Z-scores when bootstrapping
SEs)

Do you have an explanation for the different results??

Regards,
Mihai

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/