[GNC] Budget report fails in multiple currencies

[ml enquirer]

Hi Fred,

Thanks for the thought! I agree the change in value is 10,000. My point is,
basically, that I don't care about currency fluctuations in money already
spent when planning *next* year's budget.

But the 'problem' (which might just be that I need someone to explain what
a 'budget' is!) is (at least) two fold:
1) When I think 'budget' I think "planning how much I can spend in this
budget period". So I want the report to tell me that. If there are no
transactions in any child account, I don't expect a non-zero total in the
parent account. I certainly don't want a non-zero total that depends how
long I've been using gnucash. In the first year of using Gnucash, this
shows the total expense. In the 100th (hopefully!) year of using Gnucash,
this mainly shows the currency fluctuation of the history of my grocery
spending in years 0-99! These are totally different things, at least for
the typical use of an expense account like 'groceries'.
2) The budget report and the budget view seem to show the totals
aggregating in different ways. I would expect correspondence.

When you think "budgetting this year's groceries", why would you care about
having to plan for the currency fluctuation in what has already been spent,
and which is no longer available to spend, and which has no impact on what
can be spent this year? Is there another report that you'd recommend that I
use?

Let me be gently provocative: I think my described use-case is more widely
relevant, at least for expense accounts if not for asset accounts ;) But as
I keep on saying, I'm very ignorant of even basic accountancy techniques,
so feel free to (gently) teach me!

D

On Sat, Jan 7, 2023 at 6:08 PM Fred Bone <Fred at mandfb.me.uk> wrote:

> On 07 January 2023 at 10:21, ml enquirer said:
>
> > Just to add that I was wrong that this could be solved by making budgets
> > with a single period. I *think* this problem arises for any
> multi-currency
> > sub-accounts and becomes visible when you have a book which has been
> > running for many years. In that circumstance, the 'actual' column is only
> > incrementally affected by spends during the actual reporting period
> (which
> > are small compared to the cumulative spending over the years).
> >
> > Imagine a case where there is *no* spend on any sub-account in a
> reporting
> > period, but the years prior total 1,000,000 EUR and 1,000,000 GBP.
> Imagine
> > the exchange rate is 1 EUR to GBP at the start of this new 'empty' period
> > and 1 EUR to 1.01 GBP at the end. 1) The computed total at the start will
> > be 1,000,000 EUR + 1,000,000 GBP = 2,000,000 GBP. 2) The computed total
> at
> > the end will be 1,000,000 EUR + 1,000,000 GBP = 2,010,000 GBP and the
> > reported "Actual" spend will be 10,000 GBP despite nothing having been
> > spent.
>
> The change in value is indeed 10,000. What's the problem?
>
>
>