# Regarding the simulated moments in stoch\_simul

**URL:** https://forum.dynare.org/t/regarding-the-simulated-moments-in-stoch-simul/4132
**Category:** Dynare help (legacy posts)
**Created:** [3 September 2014 07:06 UTC](https://forum.dynare.org/t/regarding-the-simulated-moments-in-stoch-simul/4132 "2014-09-03T07:06:17Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![shubh](https://forum.dynare.org/letter_avatar_proxy/v4/letter/s/e19b73/32.png) [@shubh](https://forum.dynare.org/u/shubh)
#### Post date: [3 September 2014 07:06 UTC](https://forum.dynare.org/t/regarding-the-simulated-moments-in-stoch-simul/4132/1 "2014-09-03T07:06:17Z")

</div>

For the variables in exp() in the model block, are the simulated moments for those variable in exp() measured for their log values or their log-deviation ??

---

<div class="post-metadata">

### 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: [3 September 2014 09:24 UTC](https://forum.dynare.org/t/regarding-the-simulated-moments-in-stoch-simul/4132/2 "2014-09-03T09:24:33Z")

</div>

All moments in Dynare are always for the actual values of the variables. If the variable is a log-level (due to the exp-transformation) the mean will be the mean of the log-level. For second moments: they are centered moments. The centering takes the mean/steady state out. At first order, the second moments from log-levels and log-deviations from steady state are thus identical. Only at higher order, there would be a difference due to the mean not being identical to the steady state.

---

<div class="post-metadata">

### Author: ![shubh](https://forum.dynare.org/letter_avatar_proxy/v4/letter/s/e19b73/32.png) [@shubh](https://forum.dynare.org/u/shubh)
#### Post date: [3 September 2014 10:19 UTC](https://forum.dynare.org/t/regarding-the-simulated-moments-in-stoch-simul/4132/3 "2014-09-03T10:19:58Z")

</div>

so, if the order is 2.  
then say the model block declares variable u as exp(u).  
Then its empirical standard deviation is underroot(1/n(summation(ui - ubar)^2))  
where ui are the logs of simulated ui, and ubar is the empirical mean of log u.

So we can say that the standard deviation of log u is a deviation from its mean in the simulated data ? Am i right ?

---

<div class="post-metadata">

### 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: [3 September 2014 20:09 UTC](https://forum.dynare.org/t/regarding-the-simulated-moments-in-stoch-simul/4132/4 "2014-09-03T20:09:37Z")

</div>

Yes, and as everything is in logs, it has the interpretation as the standard deviation of the **percentage** deviation from the sample mean.