What is update? How many terminal solutions?

[alanlujan91]

Looking at the PortfolioConsumerType I find the following update method:

HARK/HARK/ConsumptionSaving/ConsPortfolioModel.py

Line 174 in 3ee3979

self.update()

which calls RiskyConsumerType's update

HARK/HARK/ConsumptionSaving/ConsPortfolioModel.py

Lines 180 to 181 in 3ee3979

	def update(self):
	RiskyAssetConsumerType.update(self)

which calls ConsIndShk's update

HARK/HARK/ConsumptionSaving/ConsRiskyAssetModel.py

Lines 87 to 88 in 3ee3979

	def update(self):
	IndShockConsumerType.update(self)

which finally updates the terminal solution.

HARK/HARK/ConsumptionSaving/ConsIndShockModel.py

Lines 1780 to 1794 in 3ee3979

	def update(self):
	"""
	Update the income process, the assets grid, and the terminal solution.
	Parameters
	----------
	None
	Returns
	-------
	None
	"""
	self.update_income_process()
	self.update_assets_grid()
	self.update_solution_terminal()

However, when initializing a PortfolioConsumerType, we instantiate the parent RiskyAssetConsumerType

HARK/HARK/ConsumptionSaving/ConsPortfolioModel.py

Line 170 in 3ee3979

RiskyAssetConsumerType.__init__(self, verbose=verbose, quiet=quiet, **kwds)

which instantiates the parent IndShockConsumerType

HARK/HARK/ConsumptionSaving/ConsRiskyAssetModel.py

Line 73 in 3ee3979

IndShockConsumerType.__init__(self, verbose=verbose, quiet=quiet, **kwds)

which itself updates, and calls update_terminal_solution. So, this is the second call to update_terminal_solution

But we are not done....

PortfolioConsumerType has a pre_solve method

HARK/HARK/ConsumptionSaving/ConsPortfolioModel.py

Lines 176 to 179 in 3ee3979

	def pre_solve(self):
	AgentType.pre_solve(self)
	self.update_solution_terminal()

so this is the third time we're calling update_terminal_solution by my count!

If we are lucky, it's calling the same update_terminal_solution 3 times. I don't understand this enough but I think I have been in situations where, due to poor inheritance practices, the update_teriminal_solution that I expected is not the one being run, or at least not the last one being run.

This is a big issue that sometimes makes debugging solutions harder than it needs to be.

[alanlujan91]

I think the solution is to remove the following lines

HARK/HARK/ConsumptionSaving/ConsPortfolioModel.py

Lines 174 to 178 in 3ee3979

	self.update()
	def pre_solve(self):
	AgentType.pre_solve(self)
	self.update_solution_terminal()

but this might not be the only model that does something like this

[mnwhite]

The good news is that as long as all of the classes are doing `self.update_terminal_solution()`, they will call the right one. The bad news is that we're doing redundant work. For the record, pre_solve is probably the right place for it to be called (but update is often called by pre_solve, so...?).

…

On Fri, Apr 5, 2024 at 7:44 PM Alan Lujan ***@***.***> wrote: I think the solution is to remove the following lines https://github.com/econ-ark/HARK/blob/3ee397993a1db76bbc9ae24d3196dc31ccfe4874/HARK/ConsumptionSaving/ConsPortfolioModel.py#L174-L178 but this might not be the only model that does something like this — Reply to this email directly, view it on GitHub <#1405 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADKRAFLGGIUYMNXBQBQ37C3Y34ZONAVCNFSM6AAAAABFZ5UZJ6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDANBQG43TAOBVGU> . You are receiving this because you were assigned.Message ID: ***@***.***>

[alanlujan91]

Why don't we use super?

[mnwhite]

Because I don't think we want to use the parent class version at any point. I could be wrong, however.

…

On Fri, Apr 5, 2024 at 8:04 PM Alan Lujan ***@***.***> wrote: Why don't we use super? — Reply to this email directly, view it on GitHub <#1405 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADKRAFJ6UHMA6SYQV64W66TY343ZLAVCNFSM6AAAAABFZ5UZJ6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDANBQHAYDAOJYGI> . You are receiving this because you were assigned.Message ID: ***@***.***>

[alanlujan91]

No I mean in general, super at instantiation

[Mv77]

Yeah, this is a problem. I think some agent types run the "create income process" from ConsIndShock as much as 3 times each for a single solve. Which can take longer than the solve itself...

[Mv77]

Maybe a policy for this would be that every agent type should define (not simply inherit) its full update, pre_solve, and post_solve methods? You'd be free to call super.update_whatever(...) in them, but at least you would be doing it consciously?

[mnwhite]

Yes, something like that will likely be part of the solution. This is the kind of problem that will be fixed by the parameters overhaul I'm beginning work on now, to make constructed inputs more systematic and structured. The terminal solution is a special constructed input, in that it's required.

…

On Sat, Apr 6, 2024, 10:01 AM Mateo Velásquez-Giraldo < ***@***.***> wrote: Maybe a policy for this would be that every agent type should define (not simply inherit) its full update, pre_solve, and post_solve methods? You'd be free to call super.update_whatever(...) in them, but at least you would be doing it consciously? — Reply to this email directly, view it on GitHub <#1405 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADKRAFMQLIOVAF6BEXUY6BDY3754DAVCNFSM6AAAAABFZ5UZJ6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDANBRGA4TOMJSGA> . You are receiving this because you were assigned.Message ID: ***@***.***>