# Replicate Table II, "Estimation of the Augmented
# Solow model," in Mankiw, Romer and Weil, QJE 1992
open mrw.gdt
genr lny = log(gdp85)
genr ngd = 0.05 + (popgrow/100.0)
genr lngd = log(ngd)
genr linv = log(inv/100.0)
genr lnsch = log(school/100.0)
# generate variable for testing Solow restriction
genr x3 = linv - lngd
genr x4 = lnsch - lngd
# set sample to non-oil producing countries
smpl nonoil --dummy
model1 <- ols lny const linv lngd lnsch
genr essu = $ess
genr dfu1 = $df
# restricted regression
ols lny const x3 x4
genr F1 = (($ess - essu)/1)/(essu/dfu1)
# set sample to the "better data" countries
smpl intermed --dummy --replace
model2 <- ols lny const linv lngd lnsch
genr essu = $ess
genr dfu2 = $df
# restricted regression
ols lny const x3 x4
genr F2 = (($ess - essu)/1)/(essu/dfu2)
# set sample to the OECD countries
smpl OECD --dummy --replace
model3 <- ols lny const linv lngd lnsch
genr essu = $ess
genr dfu3 = $df
# restricted regression
ols lny const x3 x4
genr F3 = (($ess - essu)/1)/(essu/dfu3)
print F1 F2 F3
# pvalues for test of Solow restriction in each sample
pvalue F 1 dfu1 F1
pvalue F 1 dfu2 F2
pvalue F 1 dfu3 F3