# Reproduce the illustrative VAR and GARCH in Stock and Watson,
# "Introduction to Econometrics", chapter 14
open sw_ch14.gdt

# set the robust std errors variant used by S and W
set force_hc on
set hc_version 1

series infl = 400 * log(PUNEW/PUNEW(-1))
diff infl 
lags d_infl LHUR
smpl 1962:1 1999:4

# run "automatic" VAR, (see equations 14.5 and 14.6)
var 4 d_infl LHUR const -r

# for comparison, try one equation manually
ols LHUR const d_infl(-1 to -4) LHUR(-1 to -4) -r

# Test for Granger causality of unemployment by inflation
omit d_infl(-1 to -4) --test-only

# GARCH model
garch 1 1 ; d_infl const d_infl(-1 to -4) LHUR(-1 to -4) -r --vcv