Add switch for QBI deduction wage/capital limitations

taxcalc/calcfunctions.py

@@ -791,8 +791,8 @@ def TaxInc(c00100, standard, c04470, c04600, MARS, e00900, e26270,
            e02100, e27200, e00650, c01000,
            PT_SSTB_income, PT_binc_w2_wages, PT_ubia_property,
            PT_qbid_rt, PT_qbid_taxinc_thd, PT_qbid_taxinc_gap,
-           PT_qbid_w2_wages_rt,
-           PT_qbid_alt_w2_wages_rt, PT_qbid_alt_property_rt,
+           PT_qbid_w2_wages_rt, PT_qbid_alt_w2_wages_rt,
+           PT_qbid_alt_property_rt, PT_qbid_limit_switch,
            c04800, qbided):
     """
     Calculates taxable income, c04800, and
@@ -813,7 +813,9 @@ def TaxInc(c00100, standard, c04470, c04600, MARS, e00900, e26270,
             upper_thd = lower_thd + pre_qbid_taxinc_gap
             if PT_SSTB_income == 1 and pre_qbid_taxinc >= upper_thd:
                 qbided = 0.
-            else:
+            # if PT_qbid_limit_switch is True, apply wage/capital
+            # limitations.
+            elif PT_qbid_limit_switch:
                 wage_cap = PT_binc_w2_wages * PT_qbid_w2_wages_rt
                 alt_cap = (PT_binc_w2_wages * PT_qbid_alt_w2_wages_rt +
                            PT_ubia_property * PT_qbid_alt_property_rt)
@@ -834,6 +836,11 @@ def TaxInc(c00100, standard, c04470, c04600, MARS, e00900, e26270,
                     prt = (pre_qbid_taxinc - lower_thd) / pre_qbid_taxinc_gap
                     adj = prt * (qbid_adjusted - cap_adjusted)
                     qbided = qbid_adjusted - adj
+            # if PT_qbid_limit_switch is False, assume all taxpayers
+            # have sufficient wage expenses and capital income to avoid
+            # QBID limitations.
+            else:
+                qbided = qbid_before_limits
         # apply taxinc cap (assuning cap rate is equal to PT_qbid_rt)
         net_cg = e00650 + c01000  # per line 34 in 2018 Pub 535 Worksheet 12-A
         taxinc_cap = PT_qbid_rt * max(0., pre_qbid_taxinc - net_cg)

taxcalc/policy_current_law.json

@@ -12358,6 +12358,32 @@
             "cps": false
         }
     },
+    "PT_qbid_limit_switch": {
+        "title": "QBID wage and capital limitations switch.",
+        "description": "A value of True imposes wage/capital limitations. Note that neither the PUF nor CPS have data on wage expenses or capital income, and therefore all taxpayers are fully subject to the QBID limitations. A value of False assumes sufficient wage and capital income to avoid QBID limitations.",
+        "notes": "",
+        "section_1": "Personal Income",
+        "section_2": "Pass-Through",
+        "indexable": false,
+        "indexed": false,
+        "type": "bool",
+        "value": [
+            {
+                "year": 2013,
+                "value": true
+            }
+        ],
+        "validators": {
+            "range": {
+                "min": false,
+                "max": true
+            }
+        },
+        "compatible_data": {
+            "puf": false,
+            "cps": false
+        }
+    },
     "AMT_em": {
         "title": "AMT exemption amount",
         "description": "The amount of AMT taxable income exempted from AMT.",

taxcalc/tests/test_calculator.py

@@ -863,6 +863,42 @@ def test_qbid_calculation():
     assert np.allclose(tc_df.qbided, tpc_df.qbid)
 
 
+def test_qbid_limit_switch():
+    """
+    Test Calculator's switch to implement wage/capital limitations
+    on QBI deduction.
+    """
+    cy = 2019
+    ref = {"PT_qbid_limit_switch": {2019: False}}
+
+    # filing unit has $500,000 in wages and $100,000 in QBI. Since
+    # the household is above the taxable income limitation threshold,
+    # with full wage/capital limitations, it does not receive a QBI
+    # deduction. With sufficent wage/capital to avoid the limitation,
+    # the filing unit receives a deduction of:
+    # $100,000 * 20% = $20,000.
+    VARS = 'RECID,MARS,e00200s,e00200p,e00200,e26270,e02000\n'
+    FUNIT = '1,2,250000,250000,500000,100000,100000'
+
+    funit_df = pd.read_csv(StringIO(VARS + FUNIT))
+    recs = Records(data=funit_df, start_year=cy,
+                   gfactors=None, weights=None)
+
+    calc_base = Calculator(policy=Policy(), records=recs)
+    calc_base.calc_all()
+
+    qbid_base = calc_base.array('qbided')
+    assert np.equal(qbid_base, 0)
+
+    pol_ref = Policy()
+    pol_ref.implement_reform(ref)
+    calc_ref = Calculator(policy=pol_ref, records=recs)
+    calc_ref.calc_all()
+
+    qbid_ref = calc_ref.array('qbided')
+    assert np.equal(qbid_ref, 20000)
+
+
 def test_calc_all_benefits_amounts(cps_subsample):
     '''
     Testing how benefits are handled in the calc_all method