# Abnormal impulse response figure

**URL:** <https://forum.dynare.org/t/abnormal-impulse-response-figure/3951>\
**Category:** Dynare help (legacy posts)\
**Created:** [6 June 2014 08:18 UTC](https://forum.dynare.org/t/abnormal-impulse-response-figure/3951 "2014-06-06T08:18:16Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![Mandy](https://forum.dynare.org/letter_avatar_proxy/v4/letter/m/b4bc9f/32.png) [@Mandy](https://forum.dynare.org/u/Mandy)\
**Post date:** [6 June 2014 08:18 UTC](https://forum.dynare.org/t/abnormal-impulse-response-figure/3951/1 "2014-06-06T08:18:16Z")

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hello!  
I run a DSGE model with dynare, but the impulse response figure seems strange.  
The figures are like waves fluctuating frequently in the first periods.

What is the problem? Thank you in advance!

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**Author:** ![Daniel\_Bendel](https://forum.dynare.org/letter_avatar_proxy/v4/letter/d/ecc23a/32.png) [@Daniel\_Bendel](https://forum.dynare.org/u/Daniel_Bendel)\
**Post date:** [6 June 2014 09:00 UTC](https://forum.dynare.org/t/abnormal-impulse-response-figure/3951/2 "2014-06-06T09:00:26Z")

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You may have wrong timing.

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**Author:** ![jpfeifer](https://forum.dynare.org/user_avatar/forum.dynare.org/jpfeifer/32/5044_2.png) [@jpfeifer](https://forum.dynare.org/u/jpfeifer)\
**Post date:** [6 June 2014 14:48 UTC](https://forum.dynare.org/t/abnormal-impulse-response-figure/3951/3 "2014-06-06T14:48:03Z")

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Exactly, wrong timing of the predetermined states often results in complex eigenvalues and thus oscillating IRFs.

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**Author:** ![Mandy](https://forum.dynare.org/letter_avatar_proxy/v4/letter/m/b4bc9f/32.png) [@Mandy](https://forum.dynare.org/u/Mandy)\
**Post date:** [7 June 2014 06:37 UTC](https://forum.dynare.org/t/abnormal-impulse-response-figure/3951/4 "2014-06-07T06:37:29Z")

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Thank you very much！but I don’t know what does “wrong timing” mean?

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**Author:** ![Mandy](https://forum.dynare.org/letter_avatar_proxy/v4/letter/m/b4bc9f/32.png) [@Mandy](https://forum.dynare.org/u/Mandy)\
**Post date:** [7 June 2014 06:54 UTC](https://forum.dynare.org/t/abnormal-impulse-response-figure/3951/5 "2014-06-07T06:54:42Z")

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Does it mean I should change the code about “stoch\_simul” ?  
I’m very confusing. Thank you!

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**Author:** ![jpfeifer](https://forum.dynare.org/user_avatar/forum.dynare.org/jpfeifer/32/5044_2.png) [@jpfeifer](https://forum.dynare.org/u/jpfeifer)\
**Post date:** [7 June 2014 07:17 UTC](https://forum.dynare.org/t/abnormal-impulse-response-figure/3951/6 "2014-06-07T07:17:36Z")

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It means there is a mistake in your model equations. Most probably a confusion of timing, i.e. you use for example k(-1) when it should be k or c when it should be c(+1).

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**Author:** ![Mandy](https://forum.dynare.org/letter_avatar_proxy/v4/letter/m/b4bc9f/32.png) [@Mandy](https://forum.dynare.org/u/Mandy)\
**Post date:** [7 June 2014 07:21 UTC](https://forum.dynare.org/t/abnormal-impulse-response-figure/3951/7 "2014-06-07T07:21:37Z")

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Oh I see. Thank you very much! I appreciate your help!🙂