Use hourly wage in overtime premium for hourly workers

changelog.d/overtime-hourly-wage.fixed.md

@@ -0,0 +1 @@
+Use `hourly_wage` when calculating `fsla_overtime_premium` for hourly workers, while keeping the prior earnings-based fallback when no hourly wage is available.

policyengine_us/tests/policy/baseline/gov/irs/income/exemptions/fsla_overtime_premium.yaml

@@ -39,3 +39,33 @@
     is_computer_scientist: true
   output:
     fsla_overtime_premium: 5105.4545
+
+- name: Overtime income premium calculation uses hourly wage for hourly workers
+  period: 2024
+  input:
+    hours_worked_last_week: 50
+    employment_income: 100000
+    hourly_wage: 20
+    is_paid_hourly: true
+    has_never_worked: false
+    is_military: false
+    is_executive_administrative_professional: true
+    is_farmer_fisher: false
+    is_computer_scientist: false
+  output:
+    fsla_overtime_premium: 5200
+
+- name: Overtime income premium falls back when hourly wage is unavailable
+  period: 2024
+  input:
+    hours_worked_last_week: 50
+    employment_income: 30000
+    hourly_wage: 0
+    is_paid_hourly: true
+    has_never_worked: false
+    is_military: false
+    is_executive_administrative_professional: true
+    is_farmer_fisher: false
+    is_computer_scientist: false
+  output:
+    fsla_overtime_premium: 2727.2727

policyengine_us/variables/household/income/person/fsla_overtime_premium.py

@@ -12,14 +12,21 @@ class fsla_overtime_premium(Variable):
     def formula_2014(person, period, parameters):
         p = parameters(period).gov.irs.income.exemption.overtime
         worked_hours = person("hours_worked_last_week", period)
+        is_paid_hourly = person("is_paid_hourly", period)
+        hourly_wage = person("hourly_wage", period)
 
         weekly_overtime_hours = max_(worked_hours - p.hours_threshold, 0)
         # Straight-time–equivalent hours in the year
         hour_equivalents = WEEKS_IN_YEAR * (
             p.hours_threshold + weekly_overtime_hours * p.rate_multiplier
         )
-        # Implied straight-time hourly wage
-        base_rate = person("employment_income", period) / hour_equivalents
+        implied_base_rate = person("employment_income", period) / hour_equivalents
+        # Hourly workers can use the ORG-backed straight-time rate directly.
+        base_rate = where(
+            is_paid_hourly & (hourly_wage > 0),
+            hourly_wage,
+            implied_base_rate,
+        )
         # Return only the overtime premium (e.g. the 50 % in time-and-a-half)
         return (
             base_rate * (p.rate_multiplier - 1) * weekly_overtime_hours * WEEKS_IN_YEAR