class testPerfForesightConsumerType(unittest.TestCase):
def setUp(self):
self.agent = PerfForesightConsumerType()
self.agent_infinite = PerfForesightConsumerType(cycles=0)
PF_dictionary = {
"CRRA": 2.5,
"DiscFac": 0.96,
"Rfree": 1.03,
"LivPrb": [0.98],
"PermGroFac": [1.01],
"T_cycle": 1,
"cycles": 0,
"AgentCount": 10000,
}
self.agent_alt = PerfForesightConsumerType(**PF_dictionary)
def test_default_solution(self):
self.agent.solve()
c = self.agent.solution[0].cFunc
self.assertEqual(c.x_list[0], -0.9805825242718447)
self.assertEqual(c.x_list[1], 0.01941747572815533)
self.assertEqual(c.y_list[0], 0)
self.assertEqual(c.y_list[1], 0.511321002804608)
self.assertEqual(c.decay_extrap, False)
def test_another_solution(self):
self.agent_alt.DiscFac = 0.90
self.agent_alt.solve()
self.assertAlmostEqual(self.agent_alt.solution[0].cFunc(10).tolist(),
3.9750093524820787)
def test_check_conditions(self):
self.agent_infinite.check_conditions()
self.assertTrue(self.agent_infinite.conditions["AIC"])
self.assertTrue(self.agent_infinite.conditions["GICRaw"])
self.assertTrue(self.agent_infinite.conditions["RIC"])
self.assertTrue(self.agent_infinite.conditions["FHWC"])
def test_simulation(self):
self.agent_infinite.solve()
# Create parameter values necessary for simulation
SimulationParams = {
"AgentCount": 10000, # Number of agents of this type
"T_sim": 120, # Number of periods to simulate
"aNrmInitMean": -6.0, # Mean of log initial assets
"aNrmInitStd": 1.0, # Standard deviation of log initial assets
"pLvlInitMean": 0.0, # Mean of log initial permanent income
"pLvlInitStd":
0.0, # Standard deviation of log initial permanent income
"PermGroFacAgg": 1.0, # Aggregate permanent income growth factor
"T_age":
None, # Age after which simulated agents are automatically killed
}
self.agent_infinite.assign_parameters(
**SimulationParams
) # This implicitly uses the assign_parameters method of AgentType
# Create PFexample object
self.agent_infinite.track_vars = ["mNrm"]
self.agent_infinite.initialize_sim()
self.agent_infinite.simulate()
self.assertAlmostEqual(
np.mean(self.agent_infinite.history["mNrm"], axis=1)[40],
-23.008063500363942,
)
self.assertAlmostEqual(
np.mean(self.agent_infinite.history["mNrm"], axis=1)[100],
-27.164608851546927,
)
## Try now with the manipulation at time step 80
self.agent_infinite.initialize_sim()
self.agent_infinite.simulate(80)
# This actually does nothing because aNrmNow is
# epiphenomenal. Probably should change mNrmNow instead
self.agent_infinite.state_now['aNrm'] += (-5.0)
self.agent_infinite.simulate(40)
self.assertAlmostEqual(
np.mean(self.agent_infinite.history["mNrm"], axis=1)[40],
-23.008063500363942,
)
self.assertAlmostEqual(
np.mean(self.agent_infinite.history["mNrm"], axis=1)[100],
-29.140261331951606,
)
def test_stable_points(self):
# Solve the constrained agent. Stable points exists only with a
# borrowing constraint.
constrained_agent = PerfForesightConsumerType(cycles=0,
BoroCnstArt=0.0)
constrained_agent.solve()
# Check against pre-computed values.
self.assertEqual(constrained_agent.solution[0].mNrmStE, 1.0)
# Check that they are both the same, since the problem is deterministic
self.assertEqual(constrained_agent.solution[0].mNrmStE,
constrained_agent.solution[0].mNrmTrg)
def plot1(Epsilon, DiscFac, PopGrowth, YearsPerGeneration, Initialk):
'''Inputs:
Epsilon: Elasticity of output with respect to capital/labour ratio
DiscFac: One period discount factor
YearPerGeneration: No. of years per generation
PopGrowth: Gross growth rate of population in one period'''
#
kMax = 0.1
# Define some parameters
Beta = DiscFac**YearsPerGeneration
xi = PopGrowth**YearsPerGeneration
Q = (1-Epsilon)*(Beta/(1+Beta))/xi
kBar = Q**(1/(1-Epsilon))
# Create an agent that will solve the consumption problem
PFagent = PerfForesightConsumerType(**init_perfect_foresight)
PFagent.cycles = 1 # let the agent live the cycle of periods just once
PFagent.T_cycle = 2 # Number of periods in the cycle
PFagent.assign_parameters(PermGroFac = [0.000001]) # Income only in the first period
PFagent.LivPrb = [1.]
PFagent.DiscFac = Beta
# Hark seems to have trouble with log-utility
# so pass rho = 1 + something small.
PFagent.CRRA = 1.001
PFagent.solve()
# Plot the OLG capital accumulation curve and 45 deg line
plt.figure(figsize=(9,6))
kt_range = np.linspace(0, kMax, 300)
# Analitical solution plot
ktp1 = Q*kt_range**Epsilon
plt.plot(kt_range, ktp1, 'b-', label='Capital accumulation curve')
plt.plot(kt_range, kt_range, 'k-', label='45 Degree line')
# Plot the path
kt_ar = Initialk
ktp1_ar = 0.
for i in range(3):
# Compute Next Period's capital using HARK
wage = (1-Epsilon)*kt_ar**Epsilon
c = PFagent.solution[0].cFunc(wage)
a = wage - c
k1 = a/xi
plt.arrow(kt_ar, ktp1_ar, 0., k1-ktp1_ar,
length_includes_head=True,
lw=0.01,
width=0.0005,
color='black',
edgecolor=None)
plt.arrow(kt_ar, k1, k1-kt_ar , 0.,
length_includes_head=True,
lw=0.01,
width=0.0005,
color='black',
edgecolor=None)
# Update arrow
kt_ar = k1
ktp1_ar = kt_ar
# Plot kbar and initial k
plt.plot(kBar, kBar, 'ro', label=r'$\bar{k}$')
plt.plot(Initialk, 0.0005, 'co', label = '$k_0$')
plt.legend()
plt.xlim(0 ,kMax)
plt.ylim(0, kMax)
plt.xlabel('$k_t$')
plt.ylabel('$k_{t+1}$')
plt.show()
return None
#
# The cell below puts these parameters into a dictionary, then gives them to `PFexample`. Note that all of these parameters *could* have been passed as part of the original dictionary; we omitted them above for simplicity.
# %% {"pycharm": {"name": "#%%\n"}}
SimulationParams = {
"AgentCount": 10000, # Number of agents of this type
"T_sim": 120, # Number of periods to simulate
"aNrmInitMean": -6.0, # Mean of log initial assets
"aNrmInitStd": 1.0, # Standard deviation of log initial assets
"pLvlInitMean": 0.0, # Mean of log initial permanent income
"pLvlInitStd": 0.0, # Standard deviation of log initial permanent income
"PermGroFacAgg": 1.0, # Aggregate permanent income growth factor
"T_age": None, # Age after which simulated agents are automatically killed
}
PFexample.assign_parameters(**SimulationParams)
# %% [markdown] {"incorrectly_encoded_metadata": "pycharm= [markdown] {\"name\": \"#%% md\\n\"}"}
# To generate simulated data, we need to specify which variables we want to track the "history" of for this instance. To do so, we set the `track_vars` attribute of our `PerfForesightConsumerType` instance to be a list of strings with the simulation variables we want to track.
#
# In this model, valid arguments to `track_vars` include $\texttt{mNrm}$, $\texttt{cNrm}$, $\texttt{aNrm}$, and $\texttt{pLvl}$. Because this model has no idiosyncratic shocks, our simulated data will be quite boring.
#
# ### Generating simulated data
#
# Before simulating, the `initialize_sim` method must be invoked. This resets our instance back to its initial state, drawing a set of initial $\texttt{aNrm}$ and $\texttt{pLvl}$ values from the specified distributions and storing them in the attributes $\texttt{aNrmNow_init}$ and $\texttt{pLvlNow_init}$. It also resets this instance's internal random number generator, so that the same initial states will be set every time `initialize_sim` is called. In models with non-trivial shocks, this also ensures that the same sequence of shocks will be generated on every simulation run.
#
# Finally, the `simulate` method can be called.
# %% {"pycharm": {"name": "#%%\n"}}
PFexample.track_vars = ['mNrm']
PFexample.initialize_sim()