Hi,

I find a question as i plot irf in second order approximation. There is a productiviy shock in the model. When i do not use pruning algorithm, the irf graphs of postive shock and negative shock are symmetric as expected. However, when i use pruning algorithm, the graphs are asymmetric. Could anyone explain it?

I have to use a algorithm like pruning or nlme in second order approximaiton, because the shock size is so small if they are not applied. what should i do to get a symmetric irf graphs under the same shock with different directions.

The code is attached as follows. You can run Main.M file to get the graph

Renjun.rar (3.5 KB)

Many Thanks