diff --git a/internal/server/v2/observation/contained_in.go b/internal/server/v2/observation/contained_in.go
index 901856d49..cf2e2b4db 100644
--- a/internal/server/v2/observation/contained_in.go
+++ b/internal/server/v2/observation/contained_in.go
@@ -186,6 +186,11 @@ func FetchContainedIn(
 	var err error
 	if store.BtGroup != nil {
 		readCollectionCache := false
+		childPlaces, err = FetchChildPlaces(
+			ctx, store, metadata, httpClient, remoteMixer, ancestor, childType)
+		if err != nil {
+			return nil, err
+		}
 		if queryDate != "" {
 			result = &pbv2.ObservationResponse{
 				ByVariable: map[string]*pbv2.VariableObservation{},
@@ -210,6 +215,10 @@ func FetchContainedIn(
 					obsByEntity := result.ByVariable[variable].ByEntity
 					data, ok := btData[variable]
 					if !ok || data == nil {
+						// If data is missing, attach empty child places.
+						for _, place := range childPlaces {
+							obsByEntity[place] = &pbv2.EntityObservation{}
+						}
 						continue
 					}
 					cohorts := data.SourceCohorts
@@ -257,11 +266,6 @@ func FetchContainedIn(
 			}
 		}
 		if !readCollectionCache {
-			childPlaces, err = FetchChildPlaces(
-				ctx, store, metadata, httpClient, remoteMixer, ancestor, childType)
-			if err != nil {
-				return nil, err
-			}
 			totalSeries := len(variables) * len(childPlaces)
 			if totalSeries > MaxSeries {
 				return nil, status.Errorf(
diff --git a/internal/server/v2/observation/golden/calculation/contained_in_2015.json b/internal/server/v2/observation/golden/calculation/contained_in_2015.json
new file mode 100644
index 000000000..e55705e6f
--- /dev/null
+++ b/internal/server/v2/observation/golden/calculation/contained_in_2015.json
@@ -0,0 +1,225 @@
+{
+  "by_variable": {
+    "Count_Person_Female": {
+      "by_entity": {
+        "wikidataId/Q159477": {
+          "ordered_facets": [
+            {
+              "observations": [
+                {
+                  "date": "1975",
+                  "value": 6170
+                },
+                {
+                  "date": "1980",
+                  "value": 13856
+                },
+                {
+                  "date": "1985",
+                  "value": 21711
+                },
+                {
+                  "date": "1995",
+                  "value": 48659
+                },
+                {
+                  "date": "2005",
+                  "value": 75313
+                }
+              ],
+              "obs_count": 5,
+              "earliest_date": "1975",
+              "latest_date": "2005"
+            }
+          ]
+        },
+        "wikidataId/Q170024": {
+          "ordered_facets": [
+            {
+              "observations": [
+                {
+                  "date": "1975",
+                  "value": 17307
+                },
+                {
+                  "date": "1980",
+                  "value": 27393
+                },
+                {
+                  "date": "1985",
+                  "value": 40165
+                },
+                {
+                  "date": "1995",
+                  "value": 59342
+                },
+                {
+                  "date": "2005",
+                  "value": 80621
+                }
+              ],
+              "obs_count": 5,
+              "earliest_date": "1975",
+              "latest_date": "2005"
+            }
+          ]
+        },
+        "wikidataId/Q175021": {
+          "ordered_facets": [
+            {
+              "observations": [
+                {
+                  "date": "1975",
+                  "value": 2645
+                },
+                {
+                  "date": "1980",
+                  "value": 4466
+                },
+                {
+                  "date": "1985",
+                  "value": 7626
+                },
+                {
+                  "date": "1995",
+                  "value": 14414
+                },
+                {
+                  "date": "2005",
+                  "value": 19075
+                }
+              ],
+              "obs_count": 5,
+              "earliest_date": "1975",
+              "latest_date": "2005"
+            }
+          ]
+        },
+        "wikidataId/Q187712": {
+          "ordered_facets": [
+            {
+              "observations": [
+                {
+                  "date": "1975",
+                  "value": 56754
+                },
+                {
+                  "date": "1980",
+                  "value": 120160
+                },
+                {
+                  "date": "1985",
+                  "value": 185783
+                },
+                {
+                  "date": "1995",
+                  "value": 291719
+                },
+                {
+                  "date": "2005",
+                  "value": 472665
+                }
+              ],
+              "obs_count": 5,
+              "earliest_date": "1975",
+              "latest_date": "2005"
+            }
+          ]
+        },
+        "wikidataId/Q188810": {
+          "ordered_facets": [
+            {
+              "observations": [
+                {
+                  "date": "1975",
+                  "value": 27535
+                },
+                {
+                  "date": "1980",
+                  "value": 56532
+                },
+                {
+                  "date": "1985",
+                  "value": 86466
+                },
+                {
+                  "date": "1995",
+                  "value": 148478
+                },
+                {
+                  "date": "2005",
+                  "value": 273339
+                }
+              ],
+              "obs_count": 5,
+              "earliest_date": "1975",
+              "latest_date": "2005"
+            }
+          ]
+        },
+        "wikidataId/Q4091": {
+          "ordered_facets": [
+            {
+              "observations": [
+                {
+                  "date": "1975",
+                  "value": 6683
+                },
+                {
+                  "date": "1980",
+                  "value": 11393
+                },
+                {
+                  "date": "1985",
+                  "value": 18343
+                },
+                {
+                  "date": "1995",
+                  "value": 30414
+                },
+                {
+                  "date": "2005",
+                  "value": 47114
+                }
+              ],
+              "obs_count": 5,
+              "earliest_date": "1975",
+              "latest_date": "2005"
+            }
+          ]
+        },
+        "wikidataId/Q613": {
+          "ordered_facets": [
+            {
+              "observations": [
+                {
+                  "date": "1975",
+                  "value": 54366
+                },
+                {
+                  "date": "1980",
+                  "value": 88587
+                },
+                {
+                  "date": "1985",
+                  "value": 123609
+                },
+                {
+                  "date": "1995",
+                  "value": 211211
+                },
+                {
+                  "date": "2005",
+                  "value": 332148
+                }
+              ],
+              "obs_count": 5,
+              "earliest_date": "1975",
+              "latest_date": "2005"
+            }
+          ]
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/internal/server/v2/observation/golden/calculation_test.go b/internal/server/v2/observation/golden/calculation_test.go
index 53a5bfb4a..a0fe7e31e 100644
--- a/internal/server/v2/observation/golden/calculation_test.go
+++ b/internal/server/v2/observation/golden/calculation_test.go
@@ -141,3 +141,70 @@ func TestCalculation(t *testing.T) {
 		t.Errorf("TestDriver() = %s", err)
 	}
 }
+
+func TestCalculationForObsCollection(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+
+	_, filename, _, _ := runtime.Caller(0)
+	goldenPath := path.Join(path.Dir(filename), "calculation")
+
+	testSuite := func(mixer pbs.MixerClient, latencyTest bool) {
+		for _, c := range []struct {
+			desc             string
+			variables        []string
+			entityExpression string
+			date             string
+			filter           *pbv2.FacetFilter
+			goldenFile       string
+		}{
+			{
+				"contained in 2015",
+				[]string{
+					"Count_Person_Female",
+				},
+				"country/ARE<-containedInPlace+{typeOf:AdministrativeArea1}",
+				"2015",
+				nil,
+				"contained_in_2015.json",
+			},
+		} {
+			goldenFile := c.goldenFile
+			resp, err := mixer.V2Observation(ctx, &pbv2.ObservationRequest{
+				Select:   []string{"variable", "entity", "date", "value"},
+				Variable: &pbv2.DcidOrExpression{Dcids: c.variables},
+				Entity:   &pbv2.DcidOrExpression{Expression: c.entityExpression},
+				Date:     c.date,
+				Filter:   c.filter,
+			})
+			if err != nil {
+				t.Errorf("could not run V2Observation (direct): %s", err)
+				continue
+			}
+			if latencyTest {
+				continue
+			}
+			if test.GenerateGolden {
+				test.UpdateGolden(resp, goldenPath, goldenFile)
+				continue
+			}
+			var expected pbv2.ObservationResponse
+			if err = test.ReadJSON(goldenPath, goldenFile, &expected); err != nil {
+				t.Errorf("Can not Unmarshal golden file: %s", err)
+				continue
+			}
+			if diff := cmp.Diff(resp, &expected, protocmp.Transform()); diff != "" {
+				t.Errorf("%s: got diff: %s", c.desc, diff)
+				continue
+			}
+		}
+	}
+	if err := test.TestDriver(
+		"TestCalculationForObsCollection",
+		&test.TestOption{UseSQLite: true, CacheSVFormula: true},
+		testSuite,
+	); err != nil {
+		t.Errorf("TestDriver() = %s", err)
+	}
+
+}
diff --git a/internal/server/v2/observation/golden/contained_in_2015/US_State.json b/internal/server/v2/observation/golden/contained_in_2015/US_State.json
index 2cbcb9e11..94406da97 100644
--- a/internal/server/v2/observation/golden/contained_in_2015/US_State.json
+++ b/internal/server/v2/observation/golden/contained_in_2015/US_State.json
@@ -2,6 +2,10 @@
   "by_variable": {
     "test_var_1": {
       "by_entity": {
+        "geoId/01": {},
+        "geoId/02": {},
+        "geoId/04": {},
+        "geoId/05": {},
         "geoId/06": {
           "ordered_facets": [
             {
@@ -17,7 +21,54 @@
               "latest_date": "2015"
             }
           ]
-        }
+        },
+        "geoId/08": {},
+        "geoId/09": {},
+        "geoId/10": {},
+        "geoId/11": {},
+        "geoId/12": {},
+        "geoId/13": {},
+        "geoId/15": {},
+        "geoId/16": {},
+        "geoId/17": {},
+        "geoId/18": {},
+        "geoId/19": {},
+        "geoId/20": {},
+        "geoId/21": {},
+        "geoId/22": {},
+        "geoId/23": {},
+        "geoId/24": {},
+        "geoId/25": {},
+        "geoId/26": {},
+        "geoId/27": {},
+        "geoId/28": {},
+        "geoId/29": {},
+        "geoId/30": {},
+        "geoId/31": {},
+        "geoId/32": {},
+        "geoId/33": {},
+        "geoId/34": {},
+        "geoId/35": {},
+        "geoId/36": {},
+        "geoId/37": {},
+        "geoId/38": {},
+        "geoId/39": {},
+        "geoId/40": {},
+        "geoId/41": {},
+        "geoId/42": {},
+        "geoId/44": {},
+        "geoId/45": {},
+        "geoId/46": {},
+        "geoId/47": {},
+        "geoId/48": {},
+        "geoId/49": {},
+        "geoId/50": {},
+        "geoId/51": {},
+        "geoId/53": {},
+        "geoId/54": {},
+        "geoId/55": {},
+        "geoId/56": {},
+        "geoId/72": {}
       }
     }
   },
diff --git a/internal/server/v2/observation/golden/contained_in_latest/CA_County.json b/internal/server/v2/observation/golden/contained_in_latest/CA_County.json
index ce8abc783..2310ff070 100644
--- a/internal/server/v2/observation/golden/contained_in_latest/CA_County.json
+++ b/internal/server/v2/observation/golden/contained_in_latest/CA_County.json
@@ -10455,7 +10455,68 @@
         }
       }
     },
-    "dummy": {}
+    "dummy": {
+      "by_entity": {
+        "geoId/06001": {},
+        "geoId/06003": {},
+        "geoId/06005": {},
+        "geoId/06007": {},
+        "geoId/06009": {},
+        "geoId/06011": {},
+        "geoId/06013": {},
+        "geoId/06015": {},
+        "geoId/06017": {},
+        "geoId/06019": {},
+        "geoId/06021": {},
+        "geoId/06023": {},
+        "geoId/06025": {},
+        "geoId/06027": {},
+        "geoId/06029": {},
+        "geoId/06031": {},
+        "geoId/06033": {},
+        "geoId/06035": {},
+        "geoId/06037": {},
+        "geoId/06039": {},
+        "geoId/06041": {},
+        "geoId/06043": {},
+        "geoId/06045": {},
+        "geoId/06047": {},
+        "geoId/06049": {},
+        "geoId/06051": {},
+        "geoId/06053": {},
+        "geoId/06055": {},
+        "geoId/06057": {},
+        "geoId/06059": {},
+        "geoId/06061": {},
+        "geoId/06063": {},
+        "geoId/06065": {},
+        "geoId/06067": {},
+        "geoId/06069": {},
+        "geoId/06071": {},
+        "geoId/06073": {},
+        "geoId/06075": {},
+        "geoId/06077": {},
+        "geoId/06079": {},
+        "geoId/06081": {},
+        "geoId/06083": {},
+        "geoId/06085": {},
+        "geoId/06087": {},
+        "geoId/06089": {},
+        "geoId/06091": {},
+        "geoId/06093": {},
+        "geoId/06095": {},
+        "geoId/06097": {},
+        "geoId/06099": {},
+        "geoId/06101": {},
+        "geoId/06103": {},
+        "geoId/06105": {},
+        "geoId/06107": {},
+        "geoId/06109": {},
+        "geoId/06111": {},
+        "geoId/06113": {},
+        "geoId/06115": {}
+      }
+    }
   },
   "facets": {
     "103184633": {
diff --git a/internal/server/v2/observation/golden/contained_in_latest/US_State.json b/internal/server/v2/observation/golden/contained_in_latest/US_State.json
index ee1169346..8484649ab 100644
--- a/internal/server/v2/observation/golden/contained_in_latest/US_State.json
+++ b/internal/server/v2/observation/golden/contained_in_latest/US_State.json
@@ -4604,7 +4604,15 @@
               "latest_date": "2023"
             }
           ]
-        }
+        },
+        "geoId/49": {},
+        "geoId/50": {},
+        "geoId/51": {},
+        "geoId/53": {},
+        "geoId/54": {},
+        "geoId/55": {},
+        "geoId/56": {},
+        "geoId/72": {}
       }
     }
   },
diff --git a/test/datacommons.db b/test/datacommons.db
index 4e3efd5ec..846ffeef2 100644
Binary files a/test/datacommons.db and b/test/datacommons.db differ