Possible incorrect commodity prices when assets have more than one output commodity with `pricing_strategy` == `scarcity`

[alexdewar]

Marking this as a question, because it isn't a confirmed bug. @ahawkes has suggested that it could be a problem though, so I've opened this issue to track it. We should investigate.

From Adam in #663 (comment):

While doing all this I did have one further concern. I wonder if the non-scarcity pricing will work ok when there is more than one output SED/SVD commodity? Don't have time to check that right now, so could we raise it as a possible issue - to be checked soon?

[ahawkes]

I've had a little time to investigate this, though not enough to be definitive.

But early indication is that indeed this is an issue, and that my method for removing the scarcity effect on prices may be too simplistic.

Ideal solution-for-now is to only use the scarcity-influenced prices (i.e. values straight from the commodity balance dual). Is that easy to do? And we keep this issue or add a new one to revisit the problem in due course.

For the investment algorithm we only need some prices - and the scarcity-influenced prices are commonly used - so it's OK to proceed with these for now.

But for further down the line - my hunch is that scarcity-influenced prices will be volatile - which could make the investment algorithm volatile.

[alexdewar]

There is an open issue for enabling scarcity-influenced prices (#625). It's quite easy to do, so I was planning on doing it soon.

I've already written code for adjusting the reduced costs for the scarcity-influenced prices (#647; it's not in a PR yet). I guess our options are that either we make it an option as planned or we just take that code out altogether. We could make scarcity pricing default to true and keep the code though. That's what I think we should probably do, unless the scarcity adjustment code will definitely not be needed in future.

What do you think?

[ahawkes]

All good suggestions. So now default will be scarcity-influenced prices. Keep non-scarcity-influenced code and make it “enable-able” via a switch (will be interesting to see what it does!). In general, the code should support multiple “pricing philosophies”, with these two as starting points. But no need for action on this - only to note that code should be structured to easily add more approaches.

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________________________________ From: Alex Dewar ***@***.***> Sent: Thursday, July 3, 2025 9:15:08 AM To: EnergySystemsModellingLab/MUSE_2.0 ***@***.***> Cc: Hawkes, Adam D ***@***.***>; Mention ***@***.***> Subject: Re: [EnergySystemsModellingLab/MUSE_2.0] Possible incorrect commodity prices when assets have more than one output commodity (Issue #677) [https://avatars.githubusercontent.com/u/23149834?s=20&v=4]alexdewar left a comment (EnergySystemsModellingLab/MUSE2#677)<#677 (comment)> There is an open issue for enabling scarcity-influenced prices (#625<#625>). It's quite easy to do, so I was planning on doing it soon. I've already written code for adjusting the reduced costs for the scarcity-influenced prices (#647<#647>; it's not in a PR yet). I guess our options are that either we make it an option as planned or we just take that code out altogether. We could make scarcity pricing default to true and keep the code though. That's what I think we should probably do, unless the scarcity adjustment code will definitely not be needed in future. What do you think? — Reply to this email directly, view it on GitHub<#677 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AC37JLMDOHM4PKIIFRY2AFD3GTRAZAVCNFSM6AAAAACAQ7NTKOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTAMZRGMZDCNZTGA>. You are receiving this because you were mentioned.Message ID: ***@***.***>