def large_blp_simulation() -> SimulationFixture:
"""Solve a simulation with 20 markets, varying numbers of products per market, a linear constant, log-linear
coefficients on prices, a linear/nonlinear/cost characteristic, another three linear characteristics, another two
cost characteristics, demographics interacted with prices and the linear/nonlinear/cost characteristic, dense
parameter matrices, a log-linear cost specification, and local differentiation instruments.
"""
id_data = build_id_data(T=20, J=20, F=9)
keep = np.arange(id_data.size)
np.random.RandomState(0).shuffle(keep)
id_data = id_data[keep[:int(0.5 * id_data.size)]]
simulation = Simulation(
product_formulations=(Formulation('1 + x + y + z + q'),
Formulation('0 + I(-prices) + x'),
Formulation('0 + log(x) + log(a) + log(b)')),
product_data={
'market_ids':
id_data.market_ids,
'firm_ids':
id_data.firm_ids,
'clustering_ids':
np.random.RandomState(2).choice(range(30), id_data.size)
},
beta=[1, 1, 2, 3, 1],
sigma=[[+0.5, 0], [-0.1, 2]],
pi=[[2, 1, 0], [0, 0, 2]],
gamma=[0.1, 0.2, 0.3],
agent_formulation=Formulation('1 + f + g'),
integration=Integration('product', 4),
xi_variance=0.00001,
omega_variance=0.00001,
correlation=0.9,
distributions=['lognormal', 'normal'],
costs_type='log',
seed=2)
simulation_results = simulation.replace_endogenous()
simulated_data_override = {
'demand_instruments':
np.c_[build_differentiation_instruments(
Formulation('0 + x + y + z + q'), simulation_results.product_data),
build_matrix(Formulation('0 + a + b'), simulation_results.
product_data)],
'supply_instruments':
np.c_[build_differentiation_instruments(
Formulation('0 + x + a + b'), simulation_results.product_data),
build_matrix(Formulation('0 + y + z + q'), simulation_results.
product_data)]
}
simulated_micro_moments = [
FirstChoiceCovarianceMoment(
X2_index=1,
demographics_index=1,
value=0,
market_ids=simulation.unique_market_ids[:5]),
FirstChoiceCovarianceMoment(
X2_index=0,
demographics_index=1,
value=0,
market_ids=simulation.unique_market_ids[-3:])
]
return simulation, simulation_results, simulated_data_override, simulated_micro_moments
def large_blp_simulation() -> SimulationFixture:
"""Solve a simulation with 20 markets, varying numbers of products per market, a linear constant, linear/nonlinear
prices, a linear/nonlinear/cost characteristic, another three linear characteristics, another two cost
characteristics, demographics interacted with prices and the linear/nonlinear/cost characteristic, dense parameter
matrices, a log-linear cost specification, and local differentiation instruments on the demand side.
"""
id_data = build_id_data(T=20, J=20, F=9)
keep = np.arange(id_data.size)
np.random.RandomState(0).shuffle(keep)
id_data = id_data[keep[:int(0.5 * id_data.size)]]
simulation = Simulation(
product_formulations=(Formulation('1 + prices + x + y + z + q'),
Formulation('0 + prices + x'),
Formulation('0 + log(x) + log(a) + log(b)')),
beta=[1, -10, 1, 2, 3, 1],
sigma=[[1, -0.1], [0, +2.0]],
gamma=[0.1, 0.2, 0.3],
product_data={
'market_ids':
id_data.market_ids,
'firm_ids':
id_data.firm_ids,
'clustering_ids':
np.random.RandomState(2).choice(range(30), id_data.size)
},
agent_formulation=Formulation('0 + f + g'),
pi=[[1, 0], [0, 2]],
integration=Integration('product', 4),
xi_variance=0.00001,
omega_variance=0.00001,
correlation=0.9,
costs_type='log',
seed=2)
simulation_results = simulation.solve()
differentiation_instruments = np.c_[
build_differentiation_instruments(Formulation('0 + x + y + z + q'),
simulation_results.product_data),
build_matrix(Formulation('0 + a + b'), simulation_results.product_data
)]
simulation_results.product_data = update_matrices(
simulation_results.product_data, {
'demand_instruments':
(differentiation_instruments,
simulation_results.product_data.demand_instruments.dtype)
})
return simulation, simulation_results
def get_blp_logit():
product_data_df = product_data.to_dict('series')
logit_products = product_data_df.copy()
inst_form = pyblp.Formulation('1 + hpwt + air + mpd + space')
X = pyblp.build_matrix(inst_form, logit_products)
# get the "original instruments"
orig_inst = np.apply_along_axis(zscore, 0,
original_inst(X, logit_products))
# solve one logit
# first argument: instruments
# second argument: logit_products (which are a copy)
problem_logit, results_logit = solve_logit_blp(np.c_[X, orig_inst],
logit_products)
save_pyblp_results(results_logit, problem_logit, filename_logit)
return results_logit
def large_blp_simulation() -> SimulationFixture:
"""Solve a simulation with 20 markets, varying numbers of products per market, a linear constant, log-linear
coefficients on prices, a linear/nonlinear/cost characteristic, another three linear characteristics, another two
cost characteristics, demographics interacted with prices and the linear/nonlinear/cost characteristic, dense
parameter matrices, a log-linear cost specification, and local differentiation instruments.
"""
id_data = build_id_data(T=20, J=20, F=9)
keep = np.arange(id_data.size)
np.random.RandomState(0).shuffle(keep)
id_data = id_data[keep[:int(0.5 * id_data.size)]]
product_ids = id_data.market_ids.copy()
for t in np.unique(id_data.market_ids):
product_ids[id_data.market_ids == t] = np.arange(
(id_data.market_ids == t).sum())
simulation = Simulation(
product_formulations=(Formulation('1 + x + y + z + q'),
Formulation('1 + I(-prices) + x'),
Formulation('0 + log(x) + log(a) + log(b)')),
product_data={
'market_ids':
id_data.market_ids,
'firm_ids':
id_data.firm_ids,
'product_ids':
product_ids,
'clustering_ids':
np.random.RandomState(2).choice(range(30), id_data.size)
},
beta=[1, 1, 2, 3, 1],
sigma=[[0, +0.0, 0], [0, +0.5, 0], [0, -0.2, 2]],
pi=[[0, 0, 0], [2, 1, 0], [0, 0, 2]],
gamma=[0.1, 0.2, 0.3],
agent_formulation=Formulation('1 + f + g'),
integration=Integration('product', 4),
xi_variance=0.00001,
omega_variance=0.00001,
correlation=0.9,
distributions=['normal', 'lognormal', 'normal'],
costs_type='log',
seed=2)
simulation_results = simulation.replace_endogenous()
simulated_data_override = {
'demand_instruments':
np.c_[build_differentiation_instruments(
Formulation('0 + x + y + z + q'), simulation_results.product_data),
build_matrix(Formulation('0 + a + b'), simulation_results.
product_data)],
'supply_instruments':
np.c_[build_differentiation_instruments(
Formulation('0 + x + a + b'), simulation_results.product_data),
build_matrix(Formulation('0 + y + z + q'), simulation_results.
product_data)]
}
simulated_micro_moments = [
DemographicExpectationMoment(product_ids=[0],
demographics_index=1,
value=0,
observations=simulation.N),
DemographicExpectationMoment(
product_ids=[None, 0],
demographics_index=1,
value=0,
observations=simulation.N,
market_ids=simulation.unique_market_ids[1:4],
market_weights=[0.2, 0.4, 0.4],
),
DemographicCovarianceMoment(
X2_index=0,
demographics_index=2,
value=0,
observations=simulation.N,
market_ids=simulation.unique_market_ids[3:5]),
DiversionProbabilityMoment(
product_id1=1,
product_id2=0,
value=0,
observations=simulation.N,
market_ids=simulation.unique_market_ids[6:10]),
DiversionProbabilityMoment(
product_id1=None,
product_id2=1,
value=0,
observations=simulation.N,
market_ids=[simulation.unique_market_ids[8]]),
DiversionProbabilityMoment(
product_id1=1,
product_id2=None,
value=0,
observations=simulation.N,
market_ids=[simulation.unique_market_ids[9]]),
DiversionCovarianceMoment(
X2_index1=1,
X2_index2=1,
value=0,
observations=simulation.N,
market_ids=[simulation.unique_market_ids[12]]),
]
return simulation, simulation_results, simulated_data_override, simulated_micro_moments
def large_blp_simulation() -> SimulationFixture:
"""Solve a simulation with 20 markets, varying numbers of products per market, a linear constant, log-linear
coefficients on prices, a linear/nonlinear/cost characteristic, another three linear characteristics, another two
cost characteristics, demographics interacted with prices and the linear/nonlinear/cost characteristic, dense
parameter matrices, a log-linear cost specification, and local differentiation instruments.
"""
id_data = build_id_data(T=20, J=20, F=9)
keep = np.arange(id_data.size)
np.random.RandomState(0).shuffle(keep)
id_data = id_data[keep[:int(0.5 * id_data.size)]]
product_ids = id_data.market_ids.copy()
for t in np.unique(id_data.market_ids):
product_ids[id_data.market_ids == t] = np.arange(
(id_data.market_ids == t).sum())
simulation = Simulation(
product_formulations=(Formulation('1 + x + y + z + q'),
Formulation('1 + I(-prices) + x'),
Formulation('0 + log(x) + log(a) + log(b)')),
product_data={
'market_ids':
id_data.market_ids,
'firm_ids':
id_data.firm_ids,
'product_ids':
product_ids,
'clustering_ids':
np.random.RandomState(2).choice(range(30), id_data.size)
},
beta=[1, 1, 2, 3, 1],
sigma=[[0, +0.0, 0], [0, +0.5, 0], [0, -0.2, 2]],
pi=[[0, 0, 0], [2, 1, 0], [0, 0, 2]],
gamma=[0.1, 0.2, 0.3],
agent_formulation=Formulation('1 + f + g'),
integration=Integration('product', 4),
xi_variance=0.00001,
omega_variance=0.00001,
correlation=0.9,
rc_types=['linear', 'log', 'linear'],
costs_type='log',
seed=2,
)
simulation_results = simulation.replace_endogenous()
simulated_data_override = {
'demand_instruments':
np.c_[build_differentiation_instruments(
Formulation('0 + x + y + z + q'), simulation_results.product_data),
build_matrix(Formulation('0 + a + b'), simulation_results.
product_data)],
'supply_instruments':
np.c_[build_differentiation_instruments(
Formulation('0 + x + a + b'), simulation_results.product_data),
build_matrix(Formulation('0 + y + z + q'), simulation_results.
product_data)]
}
inside_diversion_micro_dataset = MicroDataset(
name="diversion from 1",
observations=simulation.N,
compute_weights=lambda _, p, a: np.tile(p.product_ids == 1,
(a.size, 1, 1 + p.size)),
market_ids=simulation.unique_market_ids[6:10],
)
outside_diversion_micro_dataset = MicroDataset(
name="diversion from outside",
observations=simulation.N,
compute_weights=lambda _, p, a: np.concatenate([
np.ones((a.size, 1, 1 + p.size)),
np.zeros((a.size, p.size, 1 + p.size))
],
axis=1),
market_ids=[simulation.unique_market_ids[8]],
)
simulated_micro_moments = simulation_results.replace_micro_moment_values([
MicroMoment(
name="demographic 1 expectation for 0",
dataset=MicroDataset(
name="product 0",
observations=simulation.N,
compute_weights=lambda _, p, a: np.tile(
p.product_ids.flat == 0, (a.size, 1)),
),
value=0,
compute_values=lambda _, p, a: np.tile(a.demographics[:, [1]],
(1, p.size)),
),
MicroMoment(
name="demographic 1 expectation for 0 and outside",
dataset=MicroDataset(
name="product 0 and outside",
observations=simulation.N,
compute_weights=lambda _, p, a: np.c_[
np.ones((a.size, 1)),
np.tile(p.product_ids.flat == 0, (a.size, 1))],
market_ids=simulation.unique_market_ids[1:4],
),
value=0,
compute_values=lambda _, p, a: np.tile(a.demographics[:, [1]],
(1, 1 + p.size)),
),
MicroMoment(
name="1 to 0 diversion ratio",
dataset=inside_diversion_micro_dataset,
value=0,
compute_values=lambda _, p, a: np.concatenate([
np.zeros((a.size, p.size, 1)),
np.tile(p.product_ids.flat == 0, (a.size, p.size, 1))
],
axis=2),
),
MicroMoment(
name="outside to 1 diversion ratio",
dataset=outside_diversion_micro_dataset,
value=0,
compute_values=lambda _, p, a: np.concatenate([
np.zeros((a.size, 1 + p.size, 1)),
np.tile(p.product_ids.flat == 1, (a.size, 1 + p.size, 1))
],
axis=2),
),
MicroMoment(
name="1 to outside diversion ratio",
dataset=inside_diversion_micro_dataset,
value=0,
compute_values=lambda _, p, a: np.concatenate([
np.ones((a.size, p.size, 1)),
np.zeros((a.size, p.size, p.size))
],
axis=2),
),
MicroMoment(
name="diversion interaction",
dataset=MicroDataset(
name="inside first and second",
observations=simulation.N,
compute_weights=lambda _, p, a: np.ones(
(a.size, p.size, p.size)),
market_ids=[simulation.unique_market_ids[12]],
),
value=0,
compute_values=lambda _, p, a:
(np.tile(p.X2[:, [1]],
(a.size, 1, p.size)) * np.tile(p.X2[:, [1]].T,
(a.size, p.size, 1))),
),
])
return simulation, simulation_results, simulated_data_override, simulated_micro_moments
def test_fixed_effects(simulated_problem, ED, ES):
"""Test that absorbing different numbers of demand- and supply-side fixed effects gives rise to essentially
identical first-stage results as including indicator variables. Also test that results that should be equal when
there aren't any fixed effects are indeed equal.
"""
simulation, product_data, problem, results = simulated_problem
# test that results that should be equal when there aren't any fixed effects are indeed equal
for key in [
'delta', 'tilde_costs', 'xi', 'omega', 'xi_jacobian',
'omega_jacobian'
]:
result = getattr(results, key)
true_result = getattr(results, f'true_{key}')
assert (result is not None) == (true_result is not None)
if result is not None:
np.testing.assert_allclose(result,
true_result,
atol=1e-14,
rtol=0,
err_msg=key)
# there cannot be supply-side fixed effects if there isn't a supply side
if problem.K3 == 0:
ES = 0
if ED == ES == 0:
return
# add fixed effect IDs to the data
np.random.seed(0)
demand_names = []
supply_names = []
product_data = {k: product_data[k] for k in product_data.dtype.names}
for side, count, names in [('demand', ED, demand_names),
('supply', ES, supply_names)]:
for index in range(count):
name = f'{side}_ids{index}'
ids = np.random.choice(['a', 'b', 'c'],
product_data['market_ids'].size,
[0.7, 0.2, 0.1])
product_data[name] = ids
names.append(name)
# remove constants
product_formulations = list(problem.product_formulations).copy()
if ED > 0:
product_formulations[0] = Formulation(
f'{product_formulations[0]._formula} - 1')
product_data['demand_instruments'] = product_data[
'demand_instruments'][:, 1:]
if ES > 0:
product_formulations[2] = Formulation(
f'{product_formulations[2]._formula} - 1')
product_data['supply_instruments'] = product_data[
'supply_instruments'][:, 1:]
# build formulas for the IDs
demand_formula = ' + '.join(demand_names)
supply_formula = ' + '.join(supply_names)
# solve the first stage of a problem in which the fixed effects are absorbed
product_formulations1 = product_formulations.copy()
if ED > 0:
product_formulations1[0] = Formulation(
product_formulations[0]._formula, demand_formula)
if ES > 0:
product_formulations1[2] = Formulation(
product_formulations[2]._formula, supply_formula)
problem1 = Problem(product_formulations1, product_data,
problem.agent_formulation, simulation.agent_data)
results1 = problem1.solve(simulation.sigma, simulation.pi, steps=1)
# solve the first stage of a problem in which fixed effects are included as indicator variables
product_data2 = product_data.copy()
product_formulations2 = product_formulations.copy()
if ED > 0:
demand_indicators = build_matrix(Formulation(demand_formula),
product_data)
product_data2['demand_instruments'] = np.c_[
product_data['demand_instruments'], demand_indicators]
product_formulations2[0] = Formulation(
f'{product_formulations[0]._formula} + {demand_formula}')
if ES > 0:
supply_indicators = build_matrix(Formulation(supply_formula),
product_data)
product_data2['supply_instruments'] = np.c_[
product_data['supply_instruments'], supply_indicators]
product_formulations2[2] = Formulation(
f'{product_formulations[2]._formula} + {supply_formula}')
problem2 = Problem(product_formulations2, product_data2,
problem.agent_formulation, simulation.agent_data)
results2 = problem2.solve(simulation.sigma, simulation.pi, steps=1)
# test that all arrays expected to be identical are identical
keys = [
'theta', 'sigma', 'pi', 'beta', 'gamma', 'sigma_se', 'pi_se',
'beta_se', 'gamma_se', 'true_delta', 'true_tilde_costs', 'true_xi',
'true_omega', 'true_xi_jacobian', 'true_omega_jacobian', 'objective',
'gradient', 'sigma_gradient', 'pi_gradient'
]
for key in keys:
result1 = getattr(results1, key)
if result1 is not None:
result2 = getattr(results2, key)
if 'beta' in key or 'gamma' in key:
result2 = result2[:result1.size]
np.testing.assert_allclose(result1,
result2,
atol=1e-8,
rtol=1e-5,
err_msg=key)
