set more off

estsimp logit voted2004 yrseduc
generate pmean = .
generate plo = .
generate phi = .
generate gryred = .

local a= 1
while `a' < 18 {
setx yrseduc `a'
quietly replace gryred = `a' if _n== `a'
simqi, prval(1) genpr(pvote)
quietly egen meanp = mean(pvote)
quietly replace pmean = meanp if _n== `a'
_pctile pvote, p(2.5, 97.5)
quietly replace plo = r(r1) if _n == `a'
quietly replace phi = r(r2) if _n == `a'
quietly drop pvote meanp
local a = `a' + 1
}

label var pmean "Predicted probability"
label var plo "95% lower limit"
label var phi "95% upper limit"
label var gryred "Years of education"

graph twoway line pmean plo phi gryred, lwidth(medthick thin thin) lcolor(black black black) lpattern(solid dash dash) ytitle("Probability of voting")

drop b1 b2 plo phi pmean gryred