clear

use "C:\Documents and Settings\Garry Young\My Documents\Presentations\Interactive Variables\fake data.dta", clear

gen earthling = race

* create product of earthling & education

gen earthed = earthling * education

reg income earthling education
reg income earthling education earthed


* generate centered education variable

summarize education, meanonly
gen educmean = r(mean)
gen educ_ct = education - educmean


* show two variables in comparison

summarize education educ_ct

* create new product term using educ_ct

gen earthed_ct = educ_ct * earthling

* new set of regressions

reg income earthling educ_ct
reg income earthling educ_ct earthed_ct

* rescore dummy so that klingon = 1
* create new product term using klingon variable
* run new regressions

gen klingon = 0
replace klingon = 1 if earthling == 0
gen klinged_ct = klingon * educ_ct

reg income klingon educ_ct klinged_ct

* new regressions using age rather than race
* first center age
* then create product of centered age and education variables
* then run new regressions

summarize age, meanonly
gen agemean = r(mean)
gen age_ct = age - agemean
gen educage_ct = educ_ct * age_ct

reg income educ_ct age_ct
reg income educ_ct age_ct educage_ct