# Replication file in Dynare

**URL:** <https://forum.dynare.org/t/replication-file-in-dynare/28458>\
**Category:** Replication Attempts\
**Created:** [25 August 2026 21:13 UTC](https://forum.dynare.org/t/replication-file-in-dynare/28458 "2026-08-25T21:13:49Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Badras](https://forum.dynare.org/user_avatar/forum.dynare.org/badras/32/16654_2.png) [@Badras](https://forum.dynare.org/u/Badras)\
**Post date:** [25 August 2026 21:13 UTC](https://forum.dynare.org/t/replication-file-in-dynare/28458/1 "2026-08-25T21:13:49Z")

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Dear Prof. @jpfeifer

1. Is it possible to access your paper’s Dynare code for _“Mr. Keynes meets the Classics: Government Spending and the Real Exchange Rate”_ (published in the _Journal of Political Economy_, 2024). The journal has the files in Matlab formats and I am wondering if there is .mod file replication.

2. Out of curiosity, is there any reference or lecture notes that shows/proof why in linear DSGE models, unit root variables does not affect the slope of the policy function ?

Many thanks in advance  
Best,

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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:** [28 August 2026 09:11 UTC](https://forum.dynare.org/t/replication-file-in-dynare/28458/2 "2026-08-28T09:11:34Z")

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1. The main simulations used a global solution technique and cannot be solved in Dynare. The analytical results under perfect foresight could be replicated in Dynare.
2. What exactly do you mean with that?

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**Author:** ![Badras](https://forum.dynare.org/user_avatar/forum.dynare.org/badras/32/16654_2.png) [@Badras](https://forum.dynare.org/u/Badras)\
**Post date:** [28 August 2026 18:27 UTC](https://forum.dynare.org/t/replication-file-in-dynare/28458/3 "2026-08-28T18:27:16Z")

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Thank you Prof.,

I meant the following regarding 2)

In linear models such as gap-trend models per se. a unit root process is set to any value of our choice at the SS because, as per your previous advise, that in linear models a unit root does not affect the slope of the policy function.

Is it because the derivative in the linearization step of the unit root equation return a constant slope of 1 and therefore does not affects the slope of policy function as variables change ? However, this is not true for an AR(1) process y\_t=0.9y\_{t-t} +\epsilon per se.

Am I missing out on something here ?

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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:** [30 August 2026 11:05 UTC](https://forum.dynare.org/t/replication-file-in-dynare/28458/4 "2026-08-30T11:05:00Z")

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It’s because a unit root would simply shift both sides of involved equations up by a constant term.

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**Author:** ![Badras](https://forum.dynare.org/user_avatar/forum.dynare.org/badras/32/16654_2.png) [@Badras](https://forum.dynare.org/u/Badras)\
**Post date:** [30 August 2026 23:43 UTC](https://forum.dynare.org/t/replication-file-in-dynare/28458/5 "2026-08-30T23:43:27Z")

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Thank you prof.