***************
*** Squares ***
***************

use "C:\Users\royj\Dropbox\eco5720\Data Sets- STATA\bwght2.DTA", clear

reg bwght mage magesq
di "Turning point = " abs(_b[mage]/(2*_b[magesq]))
predict bwghth
twoway (line bwghth mage, sort)

use "C:\Users\royj\Dropbox\eco5720\Data Sets- STATA\WAGE1.DTA", clear

drop expersq
g expersq=exper^2
reg wage exper expersq
di "Turning point = " abs(_b[exper]/(2*_b[expersq]))
predict wageh
twoway (line wageh exper, sort)

********************
*** Interactions ***
********************

use "C:\Users\royj\Dropbox\eco5720\Data Sets- STATA\bwght2.DTA", clear

g mnp=mage*npvis
reg bwght mage npvis mnp

use "C:\Users\royj\Dropbox\eco5720\Data Sets- STATA\WAGE2.DTA", clear

g educIQ=educ*IQ
reg lwage educ IQ educIQ