diff --git a/taxcalc/utils.py b/taxcalc/utils.py
index 95b17dfaa..5e52f8ec1 100644
--- a/taxcalc/utils.py
+++ b/taxcalc/utils.py
@@ -310,14 +310,16 @@ def stat_dataframe(gpdf):
         Nested function that returns statistics DataFrame derived from the
         specified grouped Dataframe object, gpdf.
         """
-        sdf = pd.DataFrame()
-        unweighted_columns = set(['s006', 'num_returns_StandardDed',
-                                  'num_returns_ItemDed', 'num_returns_AMT'])
-        for col in unweighted_columns:
-            sdf[col] = gpdf.apply(unweighted_sum, col)
-        weighted_columns = set(DIST_TABLE_COLUMNS) - unweighted_columns
-        for col in weighted_columns:
-            sdf[col] = gpdf.apply(weighted_sum, col)
+        unweighted_columns = ['s006', 'num_returns_StandardDed',
+                              'num_returns_ItemDed', 'num_returns_AMT']
+        stats = list()
+        for col in DIST_TABLE_COLUMNS:
+            if col in unweighted_columns:
+                stats.append(gpdf.apply(unweighted_sum, col))
+            else:
+                stats.append(gpdf.apply(weighted_sum, col))
+        sdf = pd.DataFrame(data=np.column_stack(stats),
+                           columns=DIST_TABLE_COLUMNS)
         return sdf
 
     # main logic of create_distribution_table
@@ -369,6 +371,8 @@ def stat_dataframe(gpdf):
                 dist_table[col] /= dist_table['s006']
     # set print display format for float table elements
     pd.options.display.float_format = '{:8,.0f}'.format
+    # ensure dist_table columns are in correct order
+    assert dist_table.columns.values.tolist() == DIST_TABLE_COLUMNS
     return dist_table
 
 
@@ -536,6 +540,8 @@ def weighted_share_of_total(gpdf, colname, total):
         diffs[col] *= 100.0
     # set print display format for float table elements
     pd.options.display.float_format = '{:10,.2f}'.format
+    # ensure diffs columns are in correct order
+    assert diffs.columns.values.tolist() == DIFF_TABLE_COLUMNS
     return diffs