VA child and dependent care deduction difference with TAXSIM35

[martinholmer]

The following integration test fails. It is not yet known whether the
tax logic problem is in TAXSIM35 or in the current PEUS code, or
whether there are problems in both models. This topic is meant to
facilitate discussion of why this test fails, primarily by reporting
the results of hand calculations required to fill out the relevant tax
form.

- name: Tax unit with taxsimid 99961 in g21.its.csv and g21.ots.csv
  absolute_error_margin: 0.01
  period: 2021
  input:
    people:
      person1:
        age: 38
        employment_income: 54010
        taxable_interest_income: 5505.0
        rent: 14000
        ssi: 0  # not in TAXSIM35
        state_supplement: 0  # not in TAXSIM35
        wic: 0  # not in TAXSIM35
        ma_covid_19_essential_employee_premium_pay_program: 0  # not in TAXSIM35
      person2:
        age: 38
        employment_income: 81010
        taxable_interest_income: 5505.0
        ssi: 0  # not in TAXSIM35
        state_supplement: 0  # not in TAXSIM35
        wic: 0  # not in TAXSIM35
        ma_covid_19_essential_employee_premium_pay_program: 0  # not in TAXSIM35
      person3:
        age: 11
        ssi: 0  # not in TAXSIM35
        state_supplement: 0  # not in TAXSIM35
        wic: 0  # not in TAXSIM35
        ma_covid_19_essential_employee_premium_pay_program: 0  # not in TAXSIM35
      person4:
        age: 11
        ssi: 0  # not in TAXSIM35
        state_supplement: 0  # not in TAXSIM35
        wic: 0  # not in TAXSIM35
        ma_covid_19_essential_employee_premium_pay_program: 0  # not in TAXSIM35
    tax_units:
      tax_unit:
        members: [person1, person2, person3, person4]
        tax_unit_childcare_expenses: 8000
        premium_tax_credit: 0  # not in TAXSIM35
        local_income_tax: 0  # not in TAXSIM35
        state_sales_tax: 0  # not in TAXSIM35
        ca_use_tax: 0  # not in TAXSIM35
        il_use_tax: 0  # not in TAXSIM35
        nm_2021_income_rebate: 0  # not in TAXSIM35
        nm_additional_2021_income_rebate: 0  # not in TAXSIM35
        nm_supplemental_2021_income_rebate: 0  # not in TAXSIM35
        ny_supplemental_eitc: 0  # not in TAXSIM35
        ok_use_tax: 0  # not in TAXSIM35
        pa_use_tax: 0  # not in TAXSIM35
        vt_renter_credit: 0  # not in TAXSIM35
    spm_units:
      spm_unit:
        members: [person1, person2, person3, person4]
        snap: 0  # not in TAXSIM35
        tanf: 0  # not in TAXSIM35
    households:
      household:
        members: [person1, person2, person3, person4]
        state_fips: 51  # VA
  output:  # expected results from patched TAXSIM35 2024-02-15 version
    va_income_tax: 7062.83

[PavelMakarchuk]

@martinholmer I believe this was caused by the missing cdcc relevant expense amount deduction.

However, I believe that PE as well as TAXSIM are currently incorrect here.
While the tax form instructions seem to allow for a 3,000 or 6,000 USD deduction:

The law mentions that the ARPA cdcc cap increase is affecting the VA cdcc deduction.

Summarized, we will add the deduction in #3944 but I believe TAXSIM should also be adjusted to account for the 2021 ARPA adjustment, even if the tax form does not represent that.
However, I am open for discussion as we generally follow the form more closely
@MaxGhenis would love to get your input too

[MaxGhenis]

This TurboTax thread also indicates confusion on this.

I just double-checked the forms to verify that the Department of Taxation is incorrect when it states:

Because these provisions are already incorporated in federal and Virginia tax forms

I think you're right: it should be the $8,000/$16,000 rather than $3,000/$6,000 to reflect ARPA, the law, their published guidance, and TurboTax's behavior, even though the current form states otherwise.

[PavelMakarchuk]

based on this, we added changes in #3945 and I believe this should be adjusted in TAXSIM