# NKPC coding in Dynare

**URL:** <https://forum.dynare.org/t/nkpc-coding-in-dynare/2626>\
**Category:** Dynare help (legacy posts)\
**Created:** [11 July 2012 14:44 UTC](https://forum.dynare.org/t/nkpc-coding-in-dynare/2626 "2012-07-11T14:44:57Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Vermandel](https://forum.dynare.org/user_avatar/forum.dynare.org/vermandel/32/5866_2.png) [@Vermandel](https://forum.dynare.org/u/Vermandel)\
**Post date:** [11 July 2012 14:44 UTC](https://forum.dynare.org/t/nkpc-coding-in-dynare/2626/1 "2012-07-11T14:44:57Z")

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Hello,

I’m currently working on a model with the NKPC device, but I get a bit confused with they way of coding it. I use this functional form,

```auto

```

but regarding inflation equation, should i used this one,

```auto

```

or this one,

```auto

```

Results are strongly different, I don’t get why.

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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:** [11 July 2012 16:47 UTC](https://forum.dynare.org/t/nkpc-coding-in-dynare/2626/2 "2012-07-11T16:47:33Z")

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Results are different, because Dynare treats everything with a (+1) as being conditional expectations. Hence, the first equation holds at every point in time, while the second one holds in expectations.

```auto

```

actually is

```auto

```

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<div class="post-metadata">

**Author:** ![Vermandel](https://forum.dynare.org/user_avatar/forum.dynare.org/vermandel/32/5866_2.png) [@Vermandel](https://forum.dynare.org/u/Vermandel)\
**Post date:** [13 July 2012 11:55 UTC](https://forum.dynare.org/t/nkpc-coding-in-dynare/2626/3 "2012-07-13T11:55:25Z")

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Thanks for you answer jpfeifer.

In your opinion, should I use the first or second one equation ? I get better results with the second one.

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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:** [13 July 2012 16:12 UTC](https://forum.dynare.org/t/nkpc-coding-in-dynare/2626/4 "2012-07-13T16:12:01Z")

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Use the one that is consistent with your model.