# Sawtooth Pattern IRF

**URL:** <https://forum.dynare.org/t/sawtooth-pattern-irf/12270>\
**Category:** General DSGE Modeling\
**Created:** [14 August 2018 02:27 UTC](https://forum.dynare.org/t/sawtooth-pattern-irf/12270 "2018-08-14T02:27:40Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![magonfru1](https://forum.dynare.org/letter_avatar_proxy/v4/letter/m/c4cdca/32.png) [@magonfru1](https://forum.dynare.org/u/magonfru1)\
**Post date:** [14 August 2018 02:27 UTC](https://forum.dynare.org/t/sawtooth-pattern-irf/12270/1 "2018-08-14T02:27:41Z")

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Hi,

I have a problem while computing the IRFs of a model I am developing. Basically as the title says, when I ask Dynare to show me the IRF of the variables they appear in a sawtooth pattern. My bet is I did something wrong with the code, but I have been unable to identify the error. The model is supposed to be a doge with small firms and big firms, in order to built it I created first smaller version of the model with each type of firm that do not have this error. Would you have any suggestion on what could be the problem? (I found that someone had the same problem  
[Similar question](https://forum.dynare.org/t/zig-zag-pattern-in-irf-from-tobins-q-adjustment-cost/5273/2))

Any help is deeply appreciated  
Best  
Mario[Fullmodel.mod](https://forum.dynare.org/uploads/default/original/2X/3/3b66d2f29a126c976168946ee4fb923e4906e68c.mod) (8.2 KB)

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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:** [19 August 2018 13:37 UTC](https://forum.dynare.org/t/sawtooth-pattern-irf/12270/2 "2018-08-19T13:37:25Z")

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There is a timing issue here, giving rise to a complex eigenvalue. My guess it is related to

> [@Timing of capital in two sector economy](https://forum.dynare.org/t/timing-of-capital-in-two-sector-economy/2325):
>
> Hello all, I am building a two-sectoral model, and I have a question about the timing of sectoral-capital variables: In my model, T and N are sectors, hence kT is capital in sector T and kN is capital in sector N. Then, I assume that the economy’s aggregate capital is simply: k = kT + kN. However, I assume only one law of motion for aggregate capital such that: k = (1-delta)\*k(-1) + i - written in Dynare language. It is clear to me that k is a predetermined variable and should be treated as su…