*
* Example 16.7 page 451
* ?? Not clear what the actual data points are
* linreg doesn't quite match
*
open data tablef5-2[1].txt
data(format=prn,org=columns) 1 123 id year cost q pl sl pk sk pf sf
*
* We reorder the complete data set on q
*
order(all) q
*
set logc   = log(cost/(q*pf))
set logk   = log(pk/pf)
set logl   = log(pl/pf)
set logq   = log(q)
set logqsq = logq**2/2
smpl 6 123
linreg logc
# constant logk logl logq logqsq
*
clear logcd logkd logld
set logcd 7 123 = sqrt(.5)*(logc-logc{1})
set logkd 7 123 = sqrt(.5)*(logk-logk{1})
set logld 7 123 = sqrt(.5)*(logl-logl{1})
linreg logcd 7 123 resids
# logkd logld
density resids 7 123 xgrid fgrid
scatter(overlay=line) 2
# logq logc
# logq resids