From 158817f83ce2e089057275732642233995a2ee0e Mon Sep 17 00:00:00 2001
From: Max Ghenis <mghenis@gmail.com>
Date: Wed, 1 Jul 2026 08:54:08 +0200
Subject: [PATCH] Default US metadata to Populace

---
 .../populace-default-dataset.changed.md       |  1 +
 policyengine_api/country.py                   |  8 +++++-
 tests/unit/services/test_metadata_service.py  | 25 ++++++++++++++++++-
 3 files changed, 32 insertions(+), 2 deletions(-)
 create mode 100644 changelog.d/populace-default-dataset.changed.md

diff --git a/changelog.d/populace-default-dataset.changed.md b/changelog.d/populace-default-dataset.changed.md
new file mode 100644
index 000000000..c9d7d22f8
--- /dev/null
+++ b/changelog.d/populace-default-dataset.changed.md
@@ -0,0 +1 @@
+Default US economy metadata to the certified Populace dataset while keeping CPS and enhanced CPS as explicit non-default legacy options.
diff --git a/policyengine_api/country.py b/policyengine_api/country.py
index e671a3b63..2d978da26 100644
--- a/policyengine_api/country.py
+++ b/policyengine_api/country.py
@@ -198,11 +198,17 @@ def build_microsimulation_options(self) -> dict:
                 dict(name=2022, label="2022"),
             ]
             datasets = [
+                dict(
+                    name="default",
+                    label="Populace",
+                    title="Certified Populace dataset",
+                    default=True,
+                ),
                 dict(
                     name="cps",
                     label="CPS",
                     title="Current Population Survey",
-                    default=True,
+                    default=False,
                 ),
                 dict(
                     name="enhanced_cps",
diff --git a/tests/unit/services/test_metadata_service.py b/tests/unit/services/test_metadata_service.py
index 255c90189..e356edf94 100644
--- a/tests/unit/services/test_metadata_service.py
+++ b/tests/unit/services/test_metadata_service.py
@@ -1,6 +1,5 @@
 import pytest
 from policyengine_api.services.metadata_service import MetadataService
-from policyengine_api.country import COUNTRIES
 
 
 class TestMetadataService:
@@ -118,6 +117,30 @@ def test_verify_metadata_for_given_country(
         assert "datasets" in metadata["economy_options"]
         assert isinstance(metadata["economy_options"]["datasets"], list)
 
+    def test_us_default_dataset_is_certified_populace(self):
+        """US metadata should select the bundle-resolved Populace dataset by default."""
+        service = MetadataService()
+        metadata = service.get_metadata("us")
+
+        datasets = metadata["economy_options"]["datasets"]
+        default_datasets = [dataset for dataset in datasets if dataset.get("default")]
+
+        assert default_datasets == [
+            {
+                "name": "default",
+                "label": "Populace",
+                "title": "Certified Populace dataset",
+                "default": True,
+            }
+        ]
+        assert any(
+            dataset["name"] == "cps" and not dataset["default"] for dataset in datasets
+        )
+        assert any(
+            dataset["name"] == "enhanced_cps" and not dataset["default"]
+            for dataset in datasets
+        )
+
     @pytest.mark.parametrize(
         "country_id, expected_types",
         [