PolicyEngine / PolicyEngine/policyengine-us

Resolve all discrepancies against TAXSIM35 for 2022

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tax testing
Dominant language
Python
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163
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213
Avg merge
3d 3h
Merged PRs (30d)
96

Description

In the table below, the known issues blocking progress are:
* NONE

Unknown causes of other differences are under investigation.

```
Number of tax units (out of random samples of 100,000) with
an income tax difference between PolicyEngineUS and TAXSIM35
- sample assumptions are described below this table
- simplest sample to have differences is shown in table
- what a 'difference' means is explained below this table
--------------------------------------------------------------
: MODEL VERSIONS : : MODEL : : CAUSES OF :
PolEngUS TAXSIM35 : DIFFERENCES : : DIFFERENCES :
+ branch + patch REGION SAMPLE NUM.DIFFS RELEVANT.ISSUES
--------------------------------------------------------------
0.329.4 12/30/22 US x22 0 NONE
master 2023-05-06
-----------------------
0.213.3 12/30/22 US x22 0 NONE
master 2023-02-09 IL --- TAXSIM35 not yet ready ---
MD --- TAXSIM35 not yet ready ---
MA --- TAXSIM35 not yet ready ---
MO --- TAXSIM35 not yet ready ---
NY --- TAXSIM35 not yet ready ---
OR --- TAXSIM35 not yet ready ---
PA --- TAXSIM35 not yet ready ---
WA --- TAXSIM35 not yet ready ---
--------------------------------------------------------------
```

**Sample assumptions in two lists (each ordered from simple to more complex):**

_(1) Assumptions used for US and states without a decoupled EITC:_

**p22**: 2022 tax units consisting of married couples and single individuals with up to four dependents, with each tax unit having wages as the only source of income and no expenses of any kind.

**q22**: like p22 sample except adds social security benefits as another source of income and adds three types of expenses: rent paid, local property taxes, and mortgage interest.

**r22**: like q22 sample except adds taxable interest as an additional source of income and adds childcare expenses.

**s22**: like r22 sample except adds short-term capital gains (but not losses) as an additional source of income.

**t22**: like s22 sample except adds long-term capital gains (but not losses) as an additional source of income.

**u22**: like t22 sample except adds qualified dividends as an additional source of income.

**v22**: like u22 sample except adds taxable pension benefits as an additional source of income.

**w22**: like v22 sample except adds rent received as an additional source of income.

**x22**: like w22 sample except adds self-employment income that is from either a qualified SSTB or a qualified non-SSTB, subtracts childcare and mortgage interest expenses, and subtracts qualified dividends, short-term capital gains, and long-term capital gains.

_(2) Assumptions used for states with a decoupled EITC:_

**e22**: like p22 sample except specifies $11,010 in taxable interest income for every tax unit (in order to side-step complex state EITC decoupling rules).

**f22**: like e22 sample except adds social security benefits and taxable pension benefits as additional sources of income.

**g22**: like f22 sample except adds rent paid and childcare expenses.

**h22**: like g22 sample except adds rent received and short-term capital gains (but not losses) as additional sources of income.

**i22**: like h22 sample except adds qualified dividends and long-term capital gains (but not losses) as additional sources of income.

**j22**: like i22 sample except adds self-employment income that is from either a qualified SSTB or a qualified non-SSTB and subtracts childcare expenses.

**k22**: like j22 sample except adds local property taxes and mortage interest as expenses.

**Difference definition:**

A difference is generally defined to mean taxes from the two models being more than one cent apart. Exceptions are made when inflation indexing assumptions in the two models are not the same or when numerical precision differences between the two models cause rounding error. The following situations use a definition of difference that is larger than one cent:

**US x22 sample**: three cents (numerical precision issue)

Contributor guide

Open the contributing guide

Research direction

No source files or tests are named. Start by reproducing the PolicyEngineUS-versus-TAXSIM35 comparisons using the listed 2022 samples and model versions, then investigate the unknown causes of any differences. Done means all applicable samples agree within the stated one-cent or three-cent thresholds, with remaining exceptions explained.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
backend, data
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
15/100

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