change to relative tolerance

Author: MaxGhenis

policyengine_us_data/tests/test_datasets/test_enhanced_cps.py

@@ -72,8 +72,9 @@ def apply(self):
 
         # Calculate tax expenditure
         tax_expenditure = (income_tax_r - income_tax_b).sum()
+        pct_error = abs((tax_expenditure - target) / target)
+        TOLERANCE = 0.15
 
-        # Assert within 5bn of target
         assert (
-            abs(tax_expenditure - target) < 5e9
-        ), f"{deduction} tax expenditure {tax_expenditure/1e9:.1f}bn differs from target {target/1e9:.1f}bn by more than 5bn"
+            pct_error < TOLERANCE
+        ), f"{deduction} tax expenditure {tax_expenditure/1e9:.1f}bn differs from target {target/1e9:.1f}bn by {pct_error:.2%}"