# Klein's "Model 1" (1950)
open klein.gdt
genr W = Wp + Wg
genr A = t - 1931
genr P1 = P(-1)
genr X1 = X(-1)
# Equation-by-equation OLS
ols C 0 P P1 W 
ols I 0 P P1 K1
ols Wp 0 X X1 A
# Equation-by-equation TSLS
tsls C 0 P P1 W ; 0 G T A Wg P1 K1 X1
tsls I 0 P P1 K1 ; 0 G T A Wg P1 K1 X1
tsls Wp 0 X X1 A ; 0 G T A Wg P1 K1 X1
# Now set the model up as a system
system name="Klein Model 1"
 equation C 0 P P1 W 
 equation I 0 P P1 K1
 equation Wp 0 X X1 A
 identity P = X - T - Wp
 identity W = Wp + Wg
 identity X = C + I + G
 endog C I Wp P W X
end system
# and estimate it in various ways
estimate "Klein Model 1" method=3sls
estimate "Klein Model 1" method=fiml
estimate "Klein Model 1" method=liml