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Merge pull request #929 from sbenthall/i639
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use MarkovProcess in consumption saving models, fixes #639
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sbenthall committed Jan 21, 2021
2 parents 9a02d5c + c8c5f92 commit e2fe6cf
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Showing 4 changed files with 22 additions and 32 deletions.
2 changes: 1 addition & 1 deletion Documentation/CHANGELOG.md
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Expand Up @@ -19,7 +19,7 @@ Release Data: TBD
* calcExpectations method for taking the expectation of a distribution over a function [#884](https://github.com/econ-ark/HARK/pull/884/] (#897)[https://github.com/econ-ark/HARK/pull/897/)
* Centralizes the definition of value, marginal value, and marginal marginal value functions that use inverse-space
interpolation for problems with CRRA utility. See [#888](https://github.com/econ-ark/HARK/pull/888).
* MarkovProcess class [#902](https://github.com/econ-ark/HARK/pull/902)
* MarkovProcess class used in ConsMarkovModel, ConsRepAgentModel, ConsAggShockModel [#902](https://github.com/econ-ark/HARK/pull/902) [#929](https://github.com/econ-ark/HARK/pull/929)
* Adds a SSA life tables and methods to extract survival probabilities from them [#986](https://github.com/econ-ark/HARK/pull/906).
* Fix the return fields of `dcegm/calcCrossPoints`[#909](https://github.com/econ-ark/HARK/pull/909).
* Corrects location of constructor documentation to class string for Sphinx rendering [#908](https://github.com/econ-ark/HARK/pull/908)
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14 changes: 8 additions & 6 deletions HARK/ConsumptionSaving/ConsAggShockModel.py
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Expand Up @@ -31,6 +31,7 @@
makeGridExpMult,
)
from HARK.distribution import (
MarkovProcess,
MeanOneLogNormal,
Uniform,
combineIndepDstns,
Expand Down Expand Up @@ -2547,7 +2548,6 @@ def makeMrkvHist(self):

# Initialize the Markov history and set up transitions
MrkvNow_hist = np.zeros(self.act_T_orig, dtype=int)
cutoffs = np.cumsum(self.MrkvArray, axis=1)
loops = 0
go = True
MrkvNow = self.sow_init["MrkvNow"]
Expand All @@ -2557,9 +2557,10 @@ def makeMrkvHist(self):
# Add histories until each state has been visited at least state_T_min times
while go:
draws = Uniform(seed=loops).draw(N=self.act_T_orig)
for s in range(draws.size): # Add act_T_orig more periods
markov_process = MarkovProcess(self.MrkvArray,seed=loops)
for s in range(self.act_T_orig): # Add act_T_orig more periods
MrkvNow_hist[t] = MrkvNow
MrkvNow = np.searchsorted(cutoffs[MrkvNow, :], draws[s])
MrkvNow = markov_process.draw(MrkvNow)
t += 1

# Calculate the empirical distribution
Expand Down Expand Up @@ -2905,15 +2906,16 @@ def makeMrkvHist(self):
"""
# Initialize the Markov history and set up transitions
MrkvNow_hist = np.zeros(self.act_T, dtype=int)
cutoffs = np.cumsum(self.MrkvArray, axis=1)
MrkvNow = self.MrkvNow_init
t = 0

# Add histories until each state has been visited at least state_T_min times
draws = Uniform(seed=0).draw(N=self.act_T)
for s in range(draws.size): # Add act_T_orig more periods

markov_process = MarkovProcess(self.MrkvArray, seed= 0)
for s in range(self.act_T): # Add act_T_orig more periods
MrkvNow_hist[t] = MrkvNow
MrkvNow = np.searchsorted(cutoffs[MrkvNow, :], draws[s])
MrkvNow = markov_process.draw(MrkvNow)
t += 1

# Store the result as attribute of self
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25 changes: 6 additions & 19 deletions HARK/ConsumptionSaving/ConsMarkovModel.py
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@

from HARK.distribution import (
DiscreteDistribution,
MarkovProcess,
Uniform,
calcExpectation
)
Expand Down Expand Up @@ -1057,15 +1058,6 @@ def getMarkovStates(self):
-------
None
"""
# Draw random numbers that will be used to determine the next Markov state
if self.global_markov:
base_draws = np.ones(self.AgentCount) * Uniform(
seed=self.RNG.randint(0, 2 ** 31 - 1)
).draw(1)
else:
base_draws = Uniform(seed=self.RNG.randint(0, 2 ** 31 - 1)).draw(
self.AgentCount
)
dont_change = (
self.t_age == 0
) # Don't change Markov state for those who were just born (unless global_markov)
Expand All @@ -1076,20 +1068,15 @@ def getMarkovStates(self):
J = self.MrkvArray[0].shape[0]
MrkvPrev = self.shocks["MrkvNow"]
MrkvNow = np.zeros(self.AgentCount, dtype=int)
MrkvBoolArray = np.zeros((J, self.AgentCount))

for j in range(J):
MrkvBoolArray[j, :] = MrkvPrev == j

# Draw new Markov states for each agent
for t in range(self.T_cycle):
Cutoffs = np.cumsum(self.MrkvArray[t], axis=1)
markov_process = MarkovProcess(
self.MrkvArray[t],
seed=self.RNG.randint(0, 2 ** 31 - 1)
)
right_age = self.t_cycle == t
for j in range(J):
these = np.logical_and(right_age, MrkvBoolArray[j, :])
MrkvNow[these] = np.searchsorted(
Cutoffs[j, :], base_draws[these]
).astype(int)
MrkvNow[right_age] = markov_process.draw(MrkvPrev[right_age])
if not self.global_markov:
MrkvNow[dont_change] = MrkvPrev[dont_change]

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13 changes: 7 additions & 6 deletions HARK/ConsumptionSaving/ConsRepAgentModel.py
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@
from builtins import range
import numpy as np
from HARK.interpolation import LinearInterp, MargValueFuncCRRA
from HARK.distribution import Uniform
from HARK.distribution import (MarkovProcess, Uniform)
from HARK.ConsumptionSaving.ConsIndShockModel import (
IndShockConsumerType,
ConsumerSolution,
Expand Down Expand Up @@ -349,12 +349,13 @@ def getShocks(self):
-------
None
"""
cutoffs = np.cumsum(self.MrkvArray[self.MrkvNow, :])
MrkvDraw = Uniform(seed=self.RNG.randint(0, 2 ** 31 - 1)).draw(N=1)
self.MrkvNow = np.searchsorted(cutoffs, MrkvDraw)
self.MrkvNow = MarkovProcess(
self.MrkvArray,
seed=self.RNG.randint(0, 2 ** 31 - 1)
).draw(self.MrkvNow)

t = self.t_cycle[0]
i = self.MrkvNow[0]
i = self.MrkvNow
IncShkDstnNow = self.IncShkDstn[t - 1][i] # set current income distribution
PermGroFacNow = self.PermGroFac[t - 1][i] # and permanent growth factor
# Get random draws of income shocks from the discrete distribution
Expand All @@ -379,7 +380,7 @@ def getControls(self):
None
"""
t = self.t_cycle[0]
i = self.MrkvNow[0]
i = self.MrkvNow
self.controls["cNrmNow"] = self.solution[t].cFunc[i](self.mNrmNow)


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