I adjusted the hhincome variable for inflation and household size.
The method I used for the inflation adjustment is shown here:
https://www.census.gov/topics/income-…
The method I used for the household size adjustment is shown here:
http://www.pewsocialtrends.org/2011/1…
After those two adjustments, I have a new variable called adjhinc.
I then svyset the data, and use the epctile command with the svy option to ask for the 20th, 50th, and 80th percentile of adjhinc in each year. I use subpops for each year of: “year==20xx” & “relate==0101” & “gq==1”.
But then my results for 2005 through 2018 give me the same exact 20th, 50th, and 80th percentiles for each year. All the way down to the penny. The subpopulation sizes are each unique values, so I know I’m not mistakenly running the same year each time. And the standard errors are different for each year.
I’m having trouble comprehending this result. Literally, it seems as though it’s saying that the variation in household income percentile cutoffs each year is fully explained by changes in average household size, and inflation. But that’s obviously not true - the distribution of income changes from year to year and so should the income percentile cutoffs.
Am I missing something in the technical setup?
Here is my code:
*****************************
gen CPIadjinc=.
replace CPIadjinc=hhincome*(361/277.5) if year==2005
replace CPIadjinc=hhincome*(361/286.9) if year==2006
replace CPIadjinc=hhincome*(361/296.2) if year==2007
replace CPIadjinc=hhincome*(361/304.6) if year==2008
replace CPIadjinc=hhincome*(361/316.3) if year==2009
replace CPIadjinc=hhincome*(361/315.2) if year==2010
replace CPIadjinc=hhincome*(361/320.4) if year==2011
replace CPIadjinc=hhincome*(361/330.5) if year==2012
replace CPIadjinc=hhincome*(361/337.5) if year==2013
replace CPIadjinc=hhincome*(361/342.5) if year==2014
replace CPIadjinc=hhincome*(361/348.3) if year==2015
replace CPIadjinc=hhincome*(361/348.9) if year==2016
replace CPIadjinc=hhincome*(361/353.4) if year==2017
replace CPIadjinc=hhincome*(361/361.0) if year==2018
gen CPIandSIZEhinc=.
replace CPIandSIZEhinc=CPIadjinc/(numprec^.5)
gen CPIhincTHREE=.
replace CPIhincTHREE=CPIandSIZEhinc*(3^.5)
forvalues i=2005/2018 {
gen hincin`i’=.
}
forvalues j=2005/2018 {
replace hincinj'=1 if year==
j’ & gq==1 & relate==0101
}
svyset [iw=asecwth], sdrweight(repwt1-repwt160) vce(sdr) mse
forvalues r = 2005/2018 {
epctile CPIhincTHREE, p(20 50 80) subpop(hincin`r’) svy
}
************************************