Investigate integrating SEC 10-K EX-21 subsidiary owner info with PUDL

[zaneselvans]

Many utilities identified in FERC, EIA, and EPA data are subsidiaries owned by some larger utility holding company. Understanding these ownership relationships can be helpful in understanding the economic incentives of utilities, e.g. which electric utilities are intimately linked to natural gas companies through being owned by the same parent.

@MichaelTiemannOSC pointed me at CorpWatch which has scraped data describing these relationships from the SEC 10-K filings, where it shows up in Exhibit 21, aka EX-21. They make the data freely available for download in bulk or via a RESTful API. The 10-K is reported in XBRL, so it might be possible to download the bulk data directly from SEC and create our own database.

[MichaelTiemannOSC]

Do let me know when you attempt to process Constellation Energy Corp's 2022 report from whatever sources you can find.
I'm looking at their 2022 Sustainability Report (https://www.constellationenergy.com/content/dam/constellationenergy/pdfs/Constellation-2022-Sustainability-Report.pdf), where I find both a claim of delivering over 1.6 dekatherms of natural gas in 2021 (page 21), as well as a Scope 3 category 11 emissions disclosure totaling 69,126 kt CO2e out of a total reported Scope 3 of 93,647 kt CO2e (page 59). The problem?

ureg('1.6e9 dekatherm').to('kt CO2e')
<Quantity(84653.60969816365, 'CO2e * kt')>

Either they know how to deliver gas that burns 22% more efficiently than EPA knows about, or ??? Will be very interested to see how this ties to other disclosures and/or mass/energy/volume identities.

[cmgosnell]

Hokay. here is some learnings from a preliminary investigation:

the original PDF forms

From what i can tell, the 10k filer report all of their subsidiaries and the percentage ownership for each of those subsidiaries. seems pretty good!

Corpwatch Access

it's pretty simple! they have bulk downloads of both CSV and MySQL versions. I've only looked into the CSVs, but it seems like they both have the same structure. There is also api access! Which i assume would be nice for more one-off questions.

Columns shared with EIA

• utility name
• city
• state
• postal_code

This is actually a fair amount of information for a record linkage since location is so specific.

Data Coverage

It looks like some tables go back to 2001 but most go back to 2003 👍🏻

The one bummer in here is that it doesn't seem like the ownership % is reported in this corpwatch bulk download :-(

[zaneselvans]

That is really too bad about the percentage ownership not being available. 😢

Looking at the CorpWatch API GitHub repo, it seems like most of the codebase is like 13+ years old, and written in Perl. I wonder how far automated PDF parsing has come since then, and how hard it would be to re-write this system to use e.g. Layout Parser (GitHub repo) which @TrentonBush and @katie-lamb have been talking about for that other project. Especially if there's a well defined document structure that's shared across all of the EX-21 forms?

Edit: of course there is no standard document layout. That would be too easy. A few examples:

• AIG
• Omnicron
• ADM
• Ball

[zaneselvans]

There's also TabulaPDF, but it hasn't made a release since 2018.

[zaneselvans]

The Corpwatch DB looks like it tracks all the companies -- both parents and subsidiaries -- and counts up how many parents each subsidiary has, and how many subsidiaries each parent has, so even without the actual percentages there's some measure of how concentrated ownership is. It might be that in most cases the utility subsidiaries are wholly owned, so you could assume it's just 100%.

Big caveats on the data quality though -- it might be that misspellings or name changes mean that the counts of parents / subsidiaries are off, since they aren't using unique universal IDs.

Depending on what fraction of these relationships are simple for the electric utilities, it might be tractable to try and fill in the missing ones by hand. Or just the number of owners of a subsidiary could be taken as a gross estimate of how distributed the ownership is (assume each of 2 owners owns 50%, each of 3 owners owns 33% etc.) Wouldn't be great, but would be a lot easier than trying to parse out the wide variety of tables with nesting relationships that respondents are using to report this information.