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From | Tirthankar Chakravarty <tirthankar.chakravarty@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: How do I obtain conf. intervals for differences between percentiles of two different distributions? |
Date | Wed, 14 Apr 2010 11:14:29 +0530 |
See advice previously given here: http://www.stata.com/statalist/archive/2009-06/msg00376.html This produces bootstrap confidence interval around the difference of percentiles. T 2010/4/14 Liliana Olarte <liliana.olart@gmail.com>: > Dear Statalist : > > I am trying to estimate the wage gap between females and males by > percentiles. However, I would like to estimate conf. intervals for > the difference between the percentiles of the two distributions. ¿How > can I do this? I know cendif command does not work since cendif is > ment for computing confidence intervals, not for differences between > percentiles, but for percentile differences. > > This is the procedure I did for percentile(75) : > > - centile log_hourly_wage if gender==1, centile(75) normal > - centile log_hourly_wage if gender==2, centile(75) normal > > Results for gender==1 > --Normal, based on observed centiles -- > Variable | Obs Percentile Centile [95% Conf. Interval] > ------------------------------------------------------------------------------------------------------------------------------------ > loghourlywage | 2956 75 8.334871 8.291912 8.377831 > > > Results for gender==2 > --Normal, based on observed centiles -- > Variable | Obs Percentile Centile [95% Conf. Interval] > ------------------------------------------------------------------------------------------------------------------------------------ > loghourlywage | 1415 75 8.477972 8.412637 8.543307 > > > gap (75th centile) = 8.477972 - 8.334871=0.1431 > > These are the results when I use cendif : > > Percent Pctl_Dif Minimum Maximum > 75 .97528172 .90964651 1.0403433 > > As it can be seen from the results above, cendif is not the appropiate > command to use here. > > Regards, > Liliana > > * > * 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/ > -- To every ω-consistent recursive class κ of formulae there correspond recursive class signs r, such that neither v Gen r nor Neg(v Gen r) belongs to Flg(κ) (where v is the free variable of r). * * 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/