## two shock in two time in a loop Topic is solved

atabesh
User
Posts: 5
Joined: 1 year ago

### two shock in two time in a loop

hello my friends

I work in a recursive dynamic CGE model.
my set is
t time /1*20 /;
I want to have one shock from t=1 to t=4 (for example increase tax) and I want to have another shock from t=5 to t=20 (for example increase productivity). But I do not know how I can write a loop for this purpose. please help me

Renger
Posts: 639
Joined: 4 years ago

### Re: two shock in two time in a loop

Hi

You can loop over the whole horizon and change the parameters for the shocks. Here some example code:

Code: Select all

``````set t Periods /1*20/;

set sc /BAU, SHOCK/;

parameter parshock(sc,t)  Shock some parameters

parshock(sc,t) = 0;
parshock("SHOCK",t)\$(t.val < 5) = 2;
parshock("SHOCK",t)\$(t.val > 4) = 3;

loop(sc,
loop(t,
myparam = parshcok(sc,t);
solve model...
change capital using investments
);
);
``````
I usually add for each scenario a set like the following:

Code: Select all

``````set sc /BAU, SHOCK/,
BAU(sc)  /BAU/,
SHOCK(sc)  /SHOCK/;
``````
Now I can run the loop for a specific scenario without having to run all the other scenarios.

Code: Select all

``````loop(sc\$(shock(sc),
....
``````
Cheers
Renger
____________________________________
Enjoy modeling even more: Read my blog on modeling at The lazy economist

atabesh
User
Posts: 5
Joined: 1 year ago

### Re: two shock in two time in a loop

Thank you very much

atabesh
User
Posts: 5
Joined: 1 year ago

### Re: two shock in two time in a loop

I did exactly that, but when I increase the time, for example, from 20 to 30 years, my answer is different.
For example for t /1*20/
I increase the tax rate (t.val<5) then the average GDP decrease 0.5 % from the first year to fifth year
when t is /1*30/
and I increase the tax rate (t.val<5) then the average GDP decrease by 0.8 % from the first year to the fifth year.
I think it is wrong.