OK, gotcha. Searching your sentence, I was able to look up both 26 U.S. Code § 32 - Earned income for definitions and the new law discussing the look back, the Consolidated Appropriations Act 2021.
From the latter, this is the part that finally and definitively answers my query (and for anyone else reading this):
SEC. 211. TEMPORARY SPECIAL RULE FOR DETERMINATION OF
EARNED INCOME.
(a) IN GENERAL.—If the earned income of the taxpayer for
the taxpayer’s first taxable year beginning in 2020 is less than
the earned income of the taxpayer for the preceding taxable year,
the credits allowed under sections 24(d) and 32 of the Internal
Revenue Code of 1986 may, at the election of the taxpayer, be
determined by substituting—
(1) such earned income for the preceding taxable year,
for
(2) such earned income for the taxpayer’s first taxable
year beginning in 2020.
(b) EARNED INCOME.—
(1) IN GENERAL.—For purposes of this section, the term
‘‘earned income’’ has the meaning given such term under section
32(c) of the Internal Revenue Code of 1986.
(2) APPLICATION TO JOINT RETURNS.—For purposes of subsection (a), in the case of a joint return, the earned income
of the taxpayer for the preceding taxable year shall be the
sum of the earned income of each spouse for such preceding
taxable year.
The KEY words are in the sentence that reads: "For purposes of subsection (a)"
Subsection (a) is the applicable section referring to the prior year look back. What therefore is the conclusion I draw is that "in the case of a joint return," (which now I may credibly interpret as when back in 2019 I filed a joint return) "the earned income of the taxpayer" (take note 'the taxpayer' is singular, so this applies to my situation as an individual filer now on 2020) "for the preceding taxable year shall be the
sum of the earned income of each spouse for such preceding taxable year." MEANING: If I were to elect to use PYEI prior year earned income from 2019 in my 2020 return, I am, even as a now-divorced head of household taxpayer in 2020, forced to enter as my PYEI the entire joint sum amount originally reported in 2019 for both spouses.
So, I said this to clarify for anyone who might erroneously conclude from prior discussions that if comunity property does not apply that their individual PYEI is only the income they themselves 'earned' in 2019. That would be incorrect.
Equally incorrect would be any notion that ‘community property laws’ would some how divide the PYEI in half giving ½ now to each spouse taking the PYEI look back. As correctly noted by others, 26 U.S. Code § 32 tells us specifically that for purposes of the Earned Income Credit that "Earned Income" is "computed without regard to any community property laws".
Turns out first answer was the best answer!
THANKS SO MUCH TO ALL WHO CONTRIBUTED HERE! You're the best!!
