# PS4.5, for Table 4.5 and Application in Section 4.7
open data4-5 
ols wlfp 0 yf ym educ ue mr dr urb wh 
# retrieve relevant statistics for Wald F-test 
genr ESSU = $ess
genr DFU = $df
# omit variables one at a time - Model B 
omit mr 
# Model C 
omit ym 
# Using this final model as the restricted model retrieve ESSR and DFR 
genr ESSR = $ess
genr DFR = $df
# compute number of restrictions 
genr NR = DFR-DFU
# compute F-statistic 
genr Fc = (ESSR - ESSU)*DFU/(NR*ESSU)
# compute p-value for Fc 
pvalue F NR DFU Fc
