*
* Example 6.2, pp 102-104
*
open data tablef6-1[1].txt
data(format=prn,org=columns) 1 27 obs valueadd labor capital
*
set logl = log(labor)
set logk = log(capital)
set logl2 = .5*logl**2
set logk2 = .5*logk**2
set loglk = logl*logk
set logq  = log(valueadd)
*
* Cobb-Douglas
*
linreg logq
# constant logl logk
*
* Test of CRTS (b2+b3=1)
*
restrict(title="Test of CRTS") 1
# 2 3
# 1.0 1.0 1.0
*
* Translog
*
linreg logq
# constant logl logk logl2 logk2 loglk
*
* Test of Cobb-Douglas vs translog
*
exclude(title="Test of Cobb-Douglas as a restriction on translog")
# logl2 logk2 loglk
*
* Test of CRTS
*  b2+b3=1 and b4+b5+2b6=0
*
restrict(title="Test of CRTS in translog") 2
# 2 3
# 1.0 1.0 1.0
# 4 5 6
# 1.0 1.0 2.0 0.0
*
* Compute the elasticity of output wrt capital, as a linear combination of the
* coefficients.
*
sstats(mean) / logk>>logkmean logl>>loglmean
summarize(title="Estimate of K elasticity") %beta(3)+logkmean*%beta(5)+loglmean*%beta(6)