Personal Credit Reform (PolicyEngine#4906)

* Personal Credit Reform
Fixes PolicyEngine#4905

* reform structure

* testing

* add phase in to the basic income

* test

* circular ref.

* include ss

* remove reform

* desc.

* ss

* test fix

changelog_entry.yaml

@@ -0,0 +1,4 @@
+- bump: minor
+  changes:
+    added:
+    - Personal Credit reform.

policyengine_us/parameters/gov/contrib/ubi_center/basic_income/phase_in/include_ss_benefits_as_earnings.yaml

@@ -0,0 +1,7 @@
+description: Social Security benefits are treated as earnings under the basic income phase in if this is selected.
+values:
+  0000-01-01: false
+metadata:
+  unit: bool
+  label: SS benefits treated as earnings for basic income
+  period: year

policyengine_us/parameters/gov/contrib/ubi_center/basic_income/phase_in/per_person.yaml

@@ -0,0 +1,7 @@
+description: Basic incomes phase in per person if this is selected; otherwise, they phase in at a flat rate irrespective of household size.
+values:
+  0000-01-01: false
+metadata:
+  unit: bool
+  label: Phase in basic income per person
+  period: year

policyengine_us/parameters/gov/contrib/ubi_center/basic_income/phase_in/rate.yaml

@@ -0,0 +1,7 @@
+description: The basic income phases in at this rate.
+values:
+  0000-01-01: 1
+metadata:
+  unit: /1
+  label: Basic income phase-in rate
+  period: year

policyengine_us/tests/policy/baseline/contrib/ubi_center/basic_income_before_phase_out.yaml

@@ -3,6 +3,7 @@
   input:
     gov.contrib.ubi_center.basic_income.amount.person.flat: 100
     tax_unit_size: 2
+    basic_income_phase_in: 400
   output:
     basic_income_before_phase_out: 200
 
@@ -19,6 +20,7 @@
     tax_units:
       tax_unit:
         members: [adult, child]
+        basic_income_phase_in: 20_000
   output:
     basic_income_before_phase_out: 15_000
 
@@ -27,6 +29,7 @@
   input:
     gov.contrib.ubi_center.basic_income.amount.tax_unit.fpg_percent: 1
     tax_unit_fpg: 10_000
+    tax_unit_earned_income: 10_000
   output:
     basic_income_before_phase_out: 10_000
 
@@ -44,6 +47,7 @@
     tax_units:
       tax_unit:
         members: [adult, child]
+        basic_income_phase_in: 20_000
     families:
       family:
         members: [adult, child]
@@ -65,9 +69,32 @@
     tax_units:
       tax_unit:
         members: [adult, child]
+        basic_income_phase_in: 20_000
     families:
       family:
         members: [adult, child]
         is_married: false
   output:
     basic_income_before_phase_out: 15_000
+
+- name: Not fully phased in
+  period: 2022
+  input:
+    gov.contrib.ubi_center.basic_income.amount.person.by_age[3].amount: 10_000
+    gov.contrib.ubi_center.basic_income.amount.person.by_age[0].amount: 5_000
+    gov.contrib.ubi_center.basic_income.amount.person.marriage_bonus: 0.2
+    people:
+      adult:
+        age: 26
+      child:
+        age: 4
+    tax_units:
+      tax_unit:
+        members: [adult, child]
+        basic_income_phase_in: 12_000
+    families:
+      family:
+        members: [adult, child]
+        is_married: false
+  output:
+    basic_income_before_phase_out: 12_000

policyengine_us/tests/policy/baseline/contrib/ubi_center/basic_income_phase_in.yaml

@@ -0,0 +1,35 @@
+- name: Three people phased in at 70% with earned income
+  period: 2022
+  input:
+    gov.contrib.ubi_center.basic_income.phase_in.rate: 0.7
+    gov.contrib.ubi_center.basic_income.phase_in.per_person: false
+    gov.contrib.ubi_center.basic_income.phase_in.include_ss_benefits_as_earnings: false
+    tax_unit_earned_income: 2_000
+    tax_unit_size: 3
+    tax_unit_social_security: 0
+  output:
+    basic_income_phase_in: 1_400
+
+- name: Five people phased in at 30% with earned income, phased in per person
+  period: 2022
+  input:
+    gov.contrib.ubi_center.basic_income.phase_in.rate: 0.3
+    gov.contrib.ubi_center.basic_income.phase_in.per_person: true
+    gov.contrib.ubi_center.basic_income.phase_in.include_ss_benefits_as_earnings: true
+    tax_unit_earned_income: 2_000
+    tax_unit_size: 5
+    tax_unit_social_security: 0
+  output:
+    basic_income_phase_in: 3_000
+
+- name: SS included in earnings
+  period: 2022
+  input:
+    gov.contrib.ubi_center.basic_income.phase_in.rate: 0.3
+    gov.contrib.ubi_center.basic_income.phase_in.per_person: false
+    gov.contrib.ubi_center.basic_income.phase_in.include_ss_benefits_as_earnings: true
+    tax_unit_earned_income: 2_000
+    tax_unit_size: 5
+    tax_unit_social_security: 3_000
+  output:
+    basic_income_phase_in: 1_500

policyengine_us/variables/contrib/ubi_center/basic_income/basic_income_before_phase_out.py

@@ -31,9 +31,11 @@ def formula(tax_unit, period, parameters):
         # Disability amount
         disabled = person("is_ssi_disabled", period)
         disabled_amount = tax_unit.sum(disabled * p.person.disability)
-        return (
+        base_amount = (
             total_flat_amount
             + applicable_amount_by_age
             + fpg_amount
             + disabled_amount
         )
+        phase_in_amount = tax_unit("basic_income_phase_in", period)
+        return min_(base_amount, phase_in_amount)

policyengine_us/variables/contrib/ubi_center/basic_income/basic_income_phase_in.py

@@ -0,0 +1,22 @@
+from policyengine_us.model_api import *
+
+
+class basic_income_phase_in(Variable):
+    value_type = float
+    entity = TaxUnit
+    label = "Basic income phase-in"
+    definition_period = YEAR
+    unit = USD
+
+    def formula(tax_unit, period, parameters):
+        p = parameters(period).gov.contrib.ubi_center.basic_income.phase_in
+        earnings = tax_unit("tax_unit_earned_income", period)
+        if p.include_ss_benefits_as_earnings:
+            ss_benefits = tax_unit("tax_unit_social_security", period)
+            earnings += ss_benefits
+        if p.per_person:
+            tax_unit_size = tax_unit("tax_unit_size", period)
+            rate = p.rate * tax_unit_size
+        else:
+            rate = p.rate
+        return rate * earnings