Revise Parameters class code, documentation, and tests

reform_test.py

@@ -0,0 +1,241 @@
+"""
+Test implementation of complex reform in OSPC Tax-Calculator Parameters class.
+
+SCRIPT USAGE: tax-calculator$ python reform_test.py
+
+PYLINT USAGE: pylint --disable=locally-disabled reform_test.py
+"""
+import numpy as np
+from numpy.testing import assert_array_equal
+from taxcalc.parameters import Parameters
+from taxcalc.utils import expand_array
+
+
+def main():
+    """
+    Test implementation of multi-year reform.
+    """
+    # specify dimensions of policy Parameters object
+    syr = 2013
+    nyrs = 10
+
+    # specify assumed inflation rates
+    irates = {2013: 0.02, 2014: 0.02, 2015: 0.02, 2016: 0.03, 2017: 0.03,
+              2018: 0.04, 2019: 0.04, 2020: 0.04, 2021: 0.04, 2022: 0.04}
+    ifactors = {}
+    for i in range(0, nyrs):
+        ifactors[syr + i] = 1.0 + irates[syr + i]
+    iratelist = [irates[syr + i] for i in range(0, nyrs)]
+
+    # instantiate policy Parameters object
+    ppo = Parameters(start_year=syr, budget_years=nyrs, inflation_rates=irates)
+
+    # confirm that parameters have current-law values
+    assert_array_equal(getattr(ppo, '_AMT_thd_MarriedS'),
+                       expand_array(np.array( #pylint: disable=no-member
+                           [40400, 41050]),
+                                    inflate=True, inflation_rates=iratelist,
+                                    num_years=nyrs))
+    assert_array_equal(getattr(ppo, '_EITC_c'),
+                       expand_array(np.array( #pylint: disable=no-member
+                           [[487, 3250, 5372, 6044],
+                            [496, 3305, 5460, 6143],
+                            [503, 3359, 5548, 6242]]),
+                                    inflate=True, inflation_rates=iratelist,
+                                    num_years=nyrs))
+    assert_array_equal(getattr(ppo, '_II_em'),
+                       expand_array(np.array( #pylint: disable=no-member
+                           [3900, 3950, 4000]),
+                                    inflate=True, inflation_rates=iratelist,
+                                    num_years=nyrs))
+    assert_array_equal(getattr(ppo, '_SS_Earnings_c'),
+                       expand_array(np.array( #pylint: disable=no-member
+                           [113700, 117000, 118500]),
+                                    inflate=True, inflation_rates=iratelist,
+                                    num_years=nyrs))
+
+    # specify multi-year reform using a dictionary of year_provisions dicts
+    reform = {
+        2015: {
+            '_AMT_thd_MarriedS': [60000]
+        },
+        2016: {
+            '_EITC_c': [[900, 5000, 8000, 9000]],
+            '_II_em': [7000],
+            '_SS_Earnings_c': [300000]
+        },
+        2017: {
+            '_AMT_thd_MarriedS': [80000],
+            '_SS_Earnings_c': [500000], '_SS_Earnings_c_cpi': False
+        },
+        2019: {
+            '_EITC_c': [[1200, 7000, 10000, 12000]],
+            '_II_em': [9000],
+            '_SS_Earnings_c': [700000], '_SS_Earnings_c_cpi': True
+        }
+    }
+
+    # implement reform using Parameters class update method
+    #   Note: apparently must pass update method a YEAR:PROVISIONS dictionary,
+    #         where YEAR must equal Parameters current_year (although update
+    #         method does not enforce this requirement).  The PROVISIONS are
+    #         a dictionary of parameter:value pairs (as in the reform
+    #         dictionary above).
+    assert ppo.current_year == syr
+    reform_years_list = reform.keys()
+    last_reform_year = max(reform_years_list)
+    assert last_reform_year == 2019
+    while ppo.current_year < last_reform_year:
+        ppo.increment_year()
+        if ppo.current_year in reform_years_list:
+            year_provisions = {ppo.current_year: reform[ppo.current_year]}
+            ppo.update(year_provisions)
+
+    # move policy Parameters object back in time so current_year is syr+2
+    #   Note: this would be typical usage because the first budget year
+    #         is greater than Parameters start_year.
+    ppo._current_year = ppo.start_year #pylint: disable=protected-access
+    ppo.set_year(ppo.start_year)
+    assert ppo.current_year == ppo.start_year
+    ppo.increment_year()
+    ppo.increment_year()
+    assert ppo.current_year == syr + 2
+
+    # confirm that actual parameters have expected post-reform values
+    check_amt_thd_marrieds(ppo, reform, ifactors)
+    check_eitc_c(ppo, reform, ifactors)
+    check_ii_em(ppo, reform, ifactors)
+    check_ss_earnings_c(ppo, reform, ifactors)
+
+    # normal return
+    return 0
+
+
+def check_amt_thd_marrieds(ppo, reform, ifactor):
+    """
+    Compare actual and expected _AMT_thd_MarriedS parameter values.
+    """
+    actual = {}
+    arr = getattr(ppo, '_AMT_thd_MarriedS')
+    for i in range(0, ppo.budget_years):
+        actual[ppo.start_year + i] = arr[i]
+    assert actual[2013] == 40400
+    assert actual[2014] == 41050
+    e2015 = reform[2015]['_AMT_thd_MarriedS'][0]
+    assert actual[2015] == e2015
+    e2016 = int(round(ifactor[2016] * actual[2015]))
+    assert actual[2016] == e2016
+    e2017 = reform[2017]['_AMT_thd_MarriedS'][0]
+    assert actual[2017] == e2017
+    e2018 = int(round(ifactor[2018] * actual[2017]))
+    assert actual[2018] == e2018
+    e2019 = int(round(ifactor[2019] * actual[2018]))
+    assert actual[2019] == e2019
+    e2020 = int(round(ifactor[2020] * actual[2019]))
+    assert actual[2020] == e2020
+    e2021 = int(round(ifactor[2021] * actual[2020]))
+    absdiff = abs(actual[2021] - e2021)
+    if absdiff <= 1:
+        pass # close enough for government work
+    else:
+        assert actual[2021] == e2021
+    e2022 = int(round(ifactor[2022] * actual[2021]))
+    assert actual[2022] == e2022
+
+
+def check_eitc_c(ppo, reform, ifactor):
+    """
+    Compare actual and expected _EITC_c parameter values.
+    """
+    actual = {}
+    arr = getattr(ppo, '_EITC_c')
+    alen = len(arr[0])
+    for i in range(0, ppo.budget_years):
+        actual[ppo.start_year + i] = arr[i]
+    assert_array_equal(actual[2013], [487, 3250, 5372, 6044])
+    assert_array_equal(actual[2014], [496, 3305, 5460, 6143])
+    assert_array_equal(actual[2015], [503, 3359, 5548, 6242])
+    e2016 = reform[2016]['_EITC_c'][0]
+    assert_array_equal(actual[2016], e2016)
+    e2017 = [int(round(ifactor[2017] * actual[2016][j]))
+             for j in range(0, alen)]
+    assert_array_equal(actual[2017], e2017)
+    e2018 = [int(round(ifactor[2018] * actual[2017][j]))
+             for j in range(0, alen)]
+    assert np.allclose(actual[2018], e2018, #pylint: disable=no-member
+                       rtol=0.0, atol=1.0)
+    e2019 = reform[2019]['_EITC_c'][0]
+    assert_array_equal(actual[2019], e2019)
+    e2020 = [int(round(ifactor[2020] * actual[2019][j]))
+             for j in range(0, alen)]
+    assert_array_equal(actual[2020], e2020)
+    e2021 = [int(round(ifactor[2021] * actual[2020][j]))
+             for j in range(0, alen)]
+    assert np.allclose(actual[2021], e2021, #pylint: disable=no-member
+                       rtol=0.0, atol=1.0)
+    e2022 = [int(round(ifactor[2022] * actual[2021][j]))
+             for j in range(0, alen)]
+    assert np.allclose(actual[2022], e2022, #pylint: disable=no-member
+                       rtol=0.0, atol=1.0)
+
+
+def check_ii_em(ppo, reform, ifactor):
+    """
+    Compare actual and expected _II_em parameter values.
+    """
+    actual = {}
+    arr = getattr(ppo, '_II_em')
+    for i in range(0, ppo.budget_years):
+        actual[ppo.start_year + i] = arr[i]
+    assert actual[2013] == 3900
+    assert actual[2014] == 3950
+    assert actual[2015] == 4000
+    e2016 = reform[2016]['_II_em'][0]
+    assert actual[2016] == e2016
+    e2017 = int(round(ifactor[2017] * actual[2016]))
+    assert actual[2017] == e2017
+    e2018 = int(round(ifactor[2018] * actual[2017]))
+    assert actual[2018] == e2018
+    e2019 = reform[2019]['_II_em'][0]
+    assert actual[2019] == e2019
+    e2020 = int(round(ifactor[2020] * actual[2019]))
+    assert actual[2020] == e2020
+    e2021 = int(round(ifactor[2021] * actual[2020]))
+    assert actual[2021] == e2021
+    e2022 = int(round(ifactor[2022] * actual[2021]))
+    assert actual[2022] == e2022
+
+
+def check_ss_earnings_c(ppo, reform, ifactor):
+    """
+    Compare actual and expected _SS_Earnings_c parameter values.
+    """
+    actual = {}
+    arr = getattr(ppo, '_SS_Earnings_c')
+    for i in range(0, ppo.budget_years):
+        actual[ppo.start_year + i] = arr[i]
+    assert actual[2013] == 113700
+    assert actual[2014] == 117000
+    assert actual[2015] == 118500
+    e2016 = reform[2016]['_SS_Earnings_c'][0]
+    assert actual[2016] == e2016
+    e2017 = reform[2017]['_SS_Earnings_c'][0]
+    assert actual[2017] == e2017
+    e2018 = actual[2017] # no indexing after 2017
+    assert actual[2018] == e2018
+    e2019 = reform[2019]['_SS_Earnings_c'][0]
+    assert actual[2019] == e2019
+    e2020 = int(round(ifactor[2020] * actual[2019])) # indexing after 2019
+    assert actual[2020] == e2020
+    e2021 = int(round(ifactor[2021] * actual[2020]))
+    assert actual[2021] == e2021
+    e2022 = int(round(ifactor[2022] * actual[2021]))
+    absdiff = abs(actual[2022] - e2022)
+    if absdiff <= 1:
+        pass # close enough for government work
+    else:
+        assert actual[2022] == e2022
+
+
+if __name__ == '__main__':
+    exit(main())