Hi!

I have a simple question about the transformation of the variables from levels to logs.

Lets say that the original model has the following goods market clearing condition: Y1+Y2=C1+C2+I1+I2;

If I write:

```
model;
Y1+Y2=C1+C2+I1+I2;
end;
```

The IRF will show absolute deviations from steady-state.

IF I wanted to obtained log-deviations, then I need to transform each variable with **exp()**.

I have seen many models using the following transformation for this very specific equation ( which is originaly linear)

```
model;
exp(Y1)+exp(Y2)=exp(C1)+exp(C2)+exp(I1)+exp(I2);
end;
```

BUT, the exp(Y1+Y2)=exp(Y1)*exp(Y2), then the above transformation is wrong?

How should I do this transformation?

Many thanks in advance.