Fix private rent target and add social rent calibration target

changelog.d/317.md

@@ -0,0 +1 @@
+Fix private rent target to use UK-wide figures and add social rent calibration target (#317).

policyengine_uk_data/targets/build_loss_matrix.py

@@ -287,7 +287,11 @@ def _compute_column(target: Target, ctx: _SimContext, year: int) -> np.ndarray |
         return compute_vehicles(target, ctx)
 
     # Housing
-    if name in ("housing/total_mortgage", "housing/rent_private"):
+    if name in (
+        "housing/total_mortgage",
+        "housing/rent_private",
+        "housing/rent_social",
+    ):
         return compute_housing(target, ctx)
 
     # Land and property wealth (ONS National Balance Sheet)

policyengine_uk_data/targets/compute/other.py

@@ -27,13 +27,16 @@ def compute_vehicles(target, ctx) -> np.ndarray:
 
 
 def compute_housing(target, ctx) -> np.ndarray:
-    """Compute housing targets (mortgage, private rent)."""
+    """Compute housing targets (mortgage, private rent, social rent)."""
     name = target.name
     if name == "housing/total_mortgage":
         return ctx.pe("mortgage_capital_repayment") + ctx.pe(
             "mortgage_interest_repayment"
         )
     tenure = ctx.sim.calculate("tenure_type", map_to="household").values
+    if name == "housing/rent_social":
+        is_social = (tenure == "RENT_FROM_COUNCIL") | (tenure == "RENT_FROM_HA")
+        return ctx.pe("rent") * is_social
     return ctx.pe("rent") * (tenure == "RENT_PRIVATELY")
 
 

policyengine_uk_data/targets/sources/housing.py

@@ -1,19 +1,34 @@
 """Housing affordability targets.
 
-Total mortgage payments and private rent from ONS/English Housing Survey.
+Total mortgage payments, private rent, and social rent.
 
 Sources:
-- ONS PRHI: https://www.ons.gov.uk/economy/inflationandpriceindices/bulletins/privaterentandhousepricesuk/january2025
-- English Housing Survey mortgage data
+- ONS PRHI Feb 2026: UK avg private rent £1,374/month
+  https://www.ons.gov.uk/economy/inflationandpriceindices/bulletins/privaterentandhousepricesuk/march2026
+- English Housing Survey 2023-24: avg social rent £118/week
+  https://www.gov.uk/government/statistics/english-housing-survey-2023-to-2024-rented-sectors
+- EHS + devolved stats: ~5.4m private renters, ~5.0m social renters UK-wide
 """
 
 from policyengine_uk_data.targets.schema import Target, Unit
 
-# Estimated total annual housing costs (£)
-# Private rent: avg £1,400/month × 12 × 4.7m private renters
-# Mortgage: avg £1,100/month × 12 × 7.5m owner-occupiers with mortgage
-_PRIVATE_RENT_TOTAL = 1_400 * 12 * 4.7e6
-_MORTGAGE_TOTAL = 1_100 * 12 * 7.5e6
+# Private rent: ONS PRHI UK avg £1,374/month × 5.4m UK private renters
+_PRIVATE_RENT_TOTAL = 1_374 * 12 * 5.4e6  # ~£89bn
+
+# Mortgage: avg £1,100/month × 7.5m owner-occupiers with mortgage
+_MORTGAGE_TOTAL = 1_100 * 12 * 7.5e6  # ~£99bn
+
+# Social rent: EHS 2023-24 mean £118/week × 52 × 5.0m UK social renters
+_SOCIAL_RENT_TOTAL = 118 * 52 * 5.0e6  # ~£30.7bn
+
+_EHS_REF = (
+    "https://www.gov.uk/government/statistics/"
+    "english-housing-survey-2023-to-2024-rented-sectors"
+)
+_ONS_RENT_REF = (
+    "https://www.ons.gov.uk/economy/inflationandpriceindices/"
+    "bulletins/privaterentandhousepricesuk/march2026"
+)
 
 
 def get_targets() -> list[Target]:
@@ -24,14 +39,22 @@ def get_targets() -> list[Target]:
             source="ons",
             unit=Unit.GBP,
             values={2025: _MORTGAGE_TOTAL},
-            reference_url="https://www.ons.gov.uk/economy/inflationandpriceindices/bulletins/privaterentandhousepricesuk/january2025",
+            reference_url=_ONS_RENT_REF,
         ),
         Target(
             name="housing/rent_private",
             variable="rent",
-            source="ons",
+            source="ehs",
             unit=Unit.GBP,
             values={2025: _PRIVATE_RENT_TOTAL},
-            reference_url="https://www.ons.gov.uk/economy/inflationandpriceindices/bulletins/privaterentandhousepricesuk/january2025",
+            reference_url=_ONS_RENT_REF,
+        ),
+        Target(
+            name="housing/rent_social",
+            variable="rent",
+            source="ehs",
+            unit=Unit.GBP,
+            values={2025: _SOCIAL_RENT_TOTAL},
+            reference_url=_EHS_REF,
         ),
     ]

policyengine_uk_data/tests/test_housing_targets.py

@@ -0,0 +1,77 @@
+"""Tests for housing affordability calibration targets.
+
+See: https://github.com/PolicyEngine/policyengine-uk-data/issues/317
+"""
+
+from policyengine_uk_data.targets.sources.housing import (
+    _MORTGAGE_TOTAL,
+    _PRIVATE_RENT_TOTAL,
+    _SOCIAL_RENT_TOTAL,
+    get_targets,
+)
+
+
+# ── Target values ────────────────────────────────────────────────────
+
+
+def test_private_rent_total_in_range():
+    """Private rent total should be £70bn-£110bn (5.4m × ~£1,374/mo)."""
+    assert 70e9 < _PRIVATE_RENT_TOTAL < 110e9
+
+
+def test_social_rent_total_in_range():
+    """Social rent total should be £20bn-£40bn (5.0m × ~£118/wk)."""
+    assert 20e9 < _SOCIAL_RENT_TOTAL < 40e9
+
+
+def test_mortgage_total_in_range():
+    """Mortgage total should be £80bn-£120bn (7.5m × ~£1,100/mo)."""
+    assert 80e9 < _MORTGAGE_TOTAL < 120e9
+
+
+def test_social_rent_less_than_private():
+    """Total social rent should be less than total private rent."""
+    assert _SOCIAL_RENT_TOTAL < _PRIVATE_RENT_TOTAL
+
+
+# ── Target structure ─────────────────────────────────────────────────
+
+
+def test_get_targets_returns_three():
+    """get_targets() should return mortgage, private rent, and social rent."""
+    targets = get_targets()
+    assert len(targets) == 3
+
+
+def test_target_names():
+    """Target names should match expected values."""
+    names = {t.name for t in get_targets()}
+    assert names == {
+        "housing/total_mortgage",
+        "housing/rent_private",
+        "housing/rent_social",
+    }
+
+
+def test_all_targets_have_2025():
+    """All housing targets should have a value for 2025."""
+    for t in get_targets():
+        assert 2025 in t.values, f"{t.name} missing value for 2025"
+
+
+def test_social_rent_target_variable():
+    """Social rent target should use the rent variable."""
+    targets = get_targets()
+    social = next(t for t in targets if t.name == "housing/rent_social")
+    assert social.variable == "rent"
+
+
+def test_targets_in_registry():
+    """Housing targets should appear in the global registry."""
+    from policyengine_uk_data.targets import get_all_targets
+
+    targets = get_all_targets(year=2025)
+    names = {t.name for t in targets}
+    assert "housing/rent_social" in names
+    assert "housing/rent_private" in names
+    assert "housing/total_mortgage" in names