The RATS Software Forum

can someone help me understand sign restrictions?

i am looking at the code for Uhlig(2005). suppose fed funds is my policy instrument and i want to impose a negative(sign) response on gdpc1 and gdpdef for 6 periods, how is that indicated in the code????
thanks in advance

Using the same notation as Uhlig, your KMIN will be 1 and KMAX will be 5. The arguments for UhligAccept will be

if UhligAccept(a,KMIN,KMAX+1,||-position of gdpc1,-position of gdpdef||)==0
goto reject

position of ... means the position in the list of endogenous variables. So if you define you VAR using

SYSTEM(model=mymodel)
variables gdpc1 gdpdef ...
...

your test would be

if UhligAccept(a,KMIN,KMAX+1,||-1,-2||)==0
goto reject