*! 1.0.0
cscript wherext
which wherext

* single equation model
* ---------------------

capt log close
log using wherext, replace

set seed 123456789
set obs 400
gen edu  = invnorm(uniform())
gen exp  = int(32*uniform())
gen exp2 = exp^2
gen e    = 4*invnorm(uniform())
gen inc  = 1 + edu + exp - 0.016*exp^2 + e

regress inc edu exp exp2

* extreme with se (delta-method)
wherext exp exp2

* parametric bootstrap standard errors
wherext exp exp2, boot rep(1000) kdens seed(123) saving(wherext, replace)

* non-parametric bootstrap standard errors
bs "regress inc edu exp exp2" "-0.5*_b[exp]/_b[exp2]", rep(1000)