No, not really.

The condition is
inverted.
It is basically a
demand vs. supply rule.
(It is a "hidden" price recovery mechanism.)
If the value is >0, the prices will decrease again over time. (Because it will
increase the
amounts sold ->
prices in Europe will
decrease over time)
If the value is <0, the prices will increase again over time. (Because it will
decrease the
amounts sold ->
prices in Europe will
increase over time)
<0 : this is intended for goods that are (usually)
sold a lot to balance them back to "original prices" if Player does not sell anymore.
>0 : this is intended for goods that are (usually)
bought a lot to balance them back to "original prices" if Player does not buy anymore.
So
depending on these 2 factors the setting should be made:
(basically,
how fast do you want to recover the prices and is it
import or export case)
- import or export
- high value or low value
For some "
high value produced goods" the
prices will recover faster if you do not sell anymore.
For some "l
ow value raw goods" the
prices will recover slower if you do not sell anymore.
There is usually no need to mess with such detailled settings, unless you feel that price recovery does not work correctly.
(A lot of such settings were added in
RaR by the way, but they are really meant for
fine tuning details of balancing.)
Remarks:
The feature using it tries to
simulate a realistic market behaviour with European demand/supply and Colonial demand/supply.
(It tries to connect European Market with Colonial market to a "global market".)
There are
other settings involved in this general concept of a "global market" as well.
e.g. <iPriceCorrectionPercent> that connects all European Markets (England, France, Netherlands, Spain, Portugal, ...)
Edit:
I just discovered that considering
actual gameplay some settings needed to be changed (e.g. Barley which you will most likely never import from Europe).
@XSamatan
Thanks for your post.