Fix divide-by-zero problem in behavior.py

PSLmodels · Sep 20, 2017 · a3d00c3 · a3d00c3
1 parent b21e47a
commit a3d00c3
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/taxcalc/behavior.py b/taxcalc/behavior.py
@@ -175,8 +175,11 @@ def response(calc_x, calc_y):
             else:
                 if calc_y.behavior.BE_subinc_wrt_earnings:
                     # proportional change in after-tax income
-                    pch = (calc_y.records.aftertax_income /
-                           calc_x.records.aftertax_income) - 1.
+                    with np.errstate(invalid='ignore'):
+                        pch = np.where(calc_x.records.aftertax_income > 0.,
+                                       (calc_y.records.aftertax_income /
+                                        calc_x.records.aftertax_income) - 1.,
+                                       0.)
                     inc = calc_y.behavior.BE_inc * pch * calc_x.records.e00200
                 else:
                     # dollar change in after-tax income

diff --git a/taxcalc/tests/test_behavior.py b/taxcalc/tests/test_behavior.py
@@ -52,9 +52,10 @@ def test_behavioral_response_Calculator(cps_subsample):
                         '_BE_subinc_wrt_earnings': [True]}}
     behavior_y.update_behavior(behavior1)
     assert behavior_y.has_response() is True
-    assert abs(behavior_y.BE_sub - 0.3) < 1e-9
-    assert abs(behavior_y.BE_inc - -0.1) < 1e-9
-    assert abs(behavior_y.BE_cg - 0.0) < 1e-9
+    epsilon = 1e-9
+    assert abs(behavior_y.BE_sub - 0.3) < epsilon
+    assert abs(behavior_y.BE_inc - -0.1) < epsilon
+    assert abs(behavior_y.BE_cg - 0.0) < epsilon
     calc_y_behavior1 = Behavior.response(calc_x, calc_y)
     behavior2 = {year: {'_BE_sub': [0.5], '_BE_cg': [-0.8]}}
     behavior_y.update_behavior(behavior2)