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 Bellman.ox

 ⇩ 

1. Overview

Your DP model (called MyModel here) will be derived from the Bellman class or from one of the built-in derived classes. Think of these classes as a template for each point in your state space \(\Theta\). You pick one of the templates to start with then customize to match your model.

Each Bellman class embodies a specification of the DP model, especially the iid continuous state vector, denoted \(\zeta\) which smooths choice probabilities. This customization is fundamental because the form of \(\zeta\) (or the lack thereof) determines the calculations required to iterate on Bellman's equation at each point \(\theta.\) Each derived class of Bellman substitutes customized routines ("methods") to carry out these tasks.

Thus, the choice of parent class for MyModel depends on the action value equation: $$v(\alpha;\zeta,\theta)\quad \equiv\quad U(\alpha;\theta) + \zeta_\alpha + \delta EV(\theta^{\,\prime}).$$ The state value function \(V(\theta)\) must integrate over \(\zeta.\) This is carried out internally by the virtual thetaEMax() or its replacement. It does not have to be coded by the user. The default method, thetaEMax(), assumes there is no \(\zeta.\) Thus, the default does no integration.

Solution methods are coded separately from Bellman. They are derived from the Method class and described in Methods. Some methods may only operate if the user's model is derived from a compatible class of Bellman or has other required characteristics. For example, a case of Bellman specialization is whether MyModel involves solving for reservation values. This is a different kind of continuous shock than \(\zeta\) and requires different calculations for Bellman's equation. In this case, the parent class for MyModel must derive from the OneDimensionalChoice class because reservation value models can only allow a single action variable.

2. The Minimal Template

#import "DDP"

class MyModel : Bellman {
    // declare static data members
            Utility();
    
// Optional methods to replace built-in versions
            FeasibleActions();
            Reachable();
            ThetaUtility();
            OutcomesGivenEpsilon();
            
    }

3. User-Contributed Elements of MyModel and MyCode
1. Utility()
MyModel must supply a replacement for Utility(). Since utility depends on the current state, the method must be automatic (not static). Here is an example with one state variable and one action and how they might determine utility.

#import "DDP"

struct MyModel : Bellman {
    static decl d, s;     // One decision and one state variable
    Utility();
    }
MyModel::Utility() {
    return  CV(s)*CV(d);
    }

So this is a model where \(\alpha = (d)\) and \(\theta = (s)\) and \(U(\alpha;\theta)=sd.\)

As explained elsewhere, if s contains a state variable its "value" is not simply themselves. Likewise a. Their current values are retrieved by sending them to CV(). Also, note that \(U()\) at a state is always treated as a vector-valued function in DDP . So CV(d) is a column vector. As a state variable s is a scalar at \(\theta\).

2. Reachable States

A state is unreachable if it cannot occur given initial conditions. For example, a person cannot have 20 years of labour market experience at age 18. Including unreachable states in the state space wastes computation and storage but does not cause any errors.

MyModel can optionally provide a replacement for the virtual Reachable() method. The built-in version of Reachable returns TRUE, meaning all states are marked as reachable. The user can provide a replacement with returns an indicator for whether the current state is reachable or not.

Example.
Mark as unreachable all states at which \(x\) and \(y\) add up to a value greater than 5:

MyModel::Reachable() {
    return ! (CV(x)+CV(y)> 5);
    }

StateVariables defined in DDP have their own Reachable method which are called when creating the state space and before MyModel::Reachable() is called. This means that in many cases the user does not need to code Reachable. For example, in the case of too much experience at a given age, the ActionCounter state variable will automatically prune states from a finite horizon model based on the condition.

3. Restricted Feasible Action spaces / matrices

MyModel can optionally provide a replacement for the virtual FeasibleActions() method to make the feasible choice set to vary with the endogenous state \(\theta\). That is, the action space \(A\) is really \(A(\theta)\). Again, the default is that all values constructed from the action variables added to the model are feasible.

Example.
Only action vectors with d less than or equal to the value of state variable s are feasible.
MyModel::FeasibleActions() {
    return CV(d) .<= CV(s);
    }
The dot operator .< is the element-by-element less-than operator in Ox. So this returns a vector of length equal to the number of values d takes on containing 0s and 1s. When setting up spaces DDP will call FeasibleActions at each point in the state space. It will then create a list of different feasible sets. Each point \(\theta\) contains an index into this list to ensure only feasible action values are returned by CV(d) when the model is being solved/used.
Important: feasibility must be static. That is, the conditions returned by FeasibleActions must be determined at the creation of the spaces and cannot depend on changing elements of the model. For example, suppose p is the price of units of an action d that the agent takes as given. And suppose s is the agent's income the current state. Then one might tempted to impose the budget constraint like this:
MyModel::FeasibleActions() {
    return CV(p) * CV(d) .<= CV(s);
    }
However, if p is changing due to an equilibrium calculation this is incorrect because FeasibleActions is only called once inside DP::CreatSpaces() so it cannot be used for a dynamic condition like this. Instead, Utility must impose this condition. Ox understands \(-\infty\), so you can assign a infeasible choice that value to ensure that it will not be optimal (and will be given 0 probability):
MyModel::Utility() {
    decl dv = CV(d);
    return  CV(p)*dv .<= CV(s)  .?  dv .: -.Inf;
    }
The .? … .: … operation is an inline if-statement that will check the element-by-element condition at the start and assign the other values listed depending on whether the element is TRUE or FALSE. This case if the value of p changes and a value of d is no longer affordable it will dynamically have utility equal to \(-\infty\).
4. ThetaUtility

Suppose the utility for your model has the form $$U() = f\left( \alpha; g\left(\theta\right),\eta,\epsilon\right).$$ That is, there is a function \(g()\) of the endogenous state variables that is common for all values of the IID (exogenous and semi-exogenous) state variables. If MyModel only provides the required Utility() function then \(g(\theta)\) is recomputed for each value of the IID shocks.

This inefficiency can be eliminated by providing ThetaUtility() which is called for each \(\theta\) immediately before looping over the IID exogenous state values and calling Utility(). A simple example: $$U = a(xb + e - d) + d.$$ Here \(\theta=(x),\) \(\alpha=(a)\) is a binary choice, and \(\epsilon=(e)\) an IID shock to value of \(a=1\). \(b\) and \(d\) are parameters. So \(g() = xb\), which is not expensive to recompute unnecessarily. However, in some models this \(\theta\)-constant component of utility is very involved whereas the IID contributions are simple.

struct MyModel : Bellman {
    ⋮
    static decl a, x, xb, e;
    ⋮
    ThetaUtility();
    ⋮

MyModel::ThetaUtility() {
    xb = CV(x)*b;
    }
MyModel::Utility() {
    return CV(a)*(xb+AV(e)-d) + d;
    }
    

ThetaUtility stores the computed value in a static member of the model, xb. If xb were not declared static an additional location in memory would be created for each point \(\theta.\) It can be static even though the value of the state variable \(x\) depends on the \(\theta\). As DDP moves through the state space the value of xb is updated with the current value before Utility() is called for the current value of \(\theta\) and \(\epsilon.\) In complicated models, there may be many calculations that depend on endogenous states and estimated parameters. Using ThetaUtility() not only eliminates redundant computation it does so without additional storage that grows with the state space.
5. Hooks and Update Time

MyModel can use Add() to have a static method/function called at different points in solution methods. MyModel can also use SetUpdateTime() to set when solution methods should update transition probabilities and utility of actions. This allows transitions and utility to depend on fixed and random effect variables, but if they do not wasted computations can be avoided by updating higher up in the process.

6. Auxiliary Variables

MyModel can add AuxiliaryValues for simulating outcomes and accounting for partial observability of the state. MyCode must sandwich the commands that add actions and states to the model between calls to DPparent::Initialize(…) and DPparent::CreateSpaces(…). MyModel can supply its own version of these two methods, but then they must call the parent versions. If MyModel does not have its own versions, then the prefix DPparent:: is not needed because a reference to Initialize() will refer to the parent's version.

The DPDebug class is the base for output routines and other tasks that are related to debugging and reporting.

Most classes in niqlow have a Volume member which will determine how much output is produced during execution. In particular Volume controls how much output about the dynamic program is put out during and after a solution method. You can get more output by turning up the Volume. See NoiseLevels. For example, DP::Volume = NOISY; will produce the most output and DP::Volume = SILENT; the least. The default setting for all Volume variables is QUIET, one level above SILENT.

When you call Initialize() it opens a timestamped log file. Output that is expected to be very large, like dumps of the value function or state transitions, are sent there instead of to the screen. Other parts of niqlow will write to other timestamped log files.

Author:

© 2011-2023 Christopher Ferrall

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Documentation of Items Defined in Bellman.ox  ⇧ 

 Bellman : DP

Models based on this class correspond have no continuous shocks \(\zeta\) and no ex-post smoothing.

That is, action value is utility plus discounted expected future value:

$$v\left( A(\theta) ;\cdots \right) = U(A) + \delta EV(\theta^\prime).$$

CCPs are discussed in OODP 2.1.3.

Models based on this class have choice probabilities of the form CCP1 (equation 6).

Static members of the class are inherited from the base DP class.

MyModel is derived from Bellman or from a class derived from Bellman.

Public fields
Aind		index into CList, determines \(A(\theta)\).
EV		EV(θ)
Nxt		TransStore x η-Array of feasible endogenous state indices and transitions \(P(\theta^\prime;\alpha,\eta,\theta)\).
pandv		\(v(\alpha;\epsilon,\eta,\theta)\) and \(P*()\).
Type		Integer code to classify state (InSubSample,LastT,Terminal).
Public methods
ActVal	virtual	Compute \(v(\alpha;\theta)\) for all values of \(\epsilon\) and \(\eta\).
AutoAuxiliaryValues	virtual
Bellman		Creator function for a new point in \(\Theta\), initializing the automatic (non-static) members.
CreateSpaces	static	Calls the DP version.
Delete	static	Delete the current DP model and reset.
ExogExpectedV	virtual	Completes \(v(\alpha;\cdots,\eta,\theta)\) by adding discounted expected value to utilities for a given \(\eta\).
FeasibleActions	virtual	Default \(A(\theta)\): all actions are feasible at all states, except for terminal states.
GetPandV
IgnoreExogenous	virtual	Return FALSE: Elements of the exogenous vector are looped over when computing U and EV.
Initialize	static	Base Initialize function.
InSS	virtual	Return TRUE if full iteration over exogenous values and transitions to be carried out at this point (in subsample).
KernelCCP	virtual
MedianActVal		KeaneWolpin: Computes v() and V for out-of-sample states.
MyopicActVal		For Myopic agent or StaticClock or just Initial, v=U and no need to evaluate EV.
OnlyFeasible		Extract and return rows of a matrix that correspond to feasible actions at the current state.
OutcomesGivenEpsilon	virtual	Default / virtual routine.
Reachable	virtual	Return TRUE: Default indicator function for whether the current state is reachable from initial conditions or not.
SetTheta	virtual	Sets up a single point θ in the state space.
Smooth	virtual	Default Choice Probabilities: no smoothing.
StateToStatePrediction		Compute \(P(\theta^\prime;\theta)\).
thetaEMax	virtual	Default Emax operator at \(\theta.\) Not called by User code directly Derived classes provide a replacement.
ThetaTransition		Computes the endogneous transition given \(\eta.\) Not called by User code directly Loops over all state variables to compute \(P(\theta^\prime ; \alpha, \eta )\).
ThetaUtility	virtual	Default to be replaced by user if necessary.
UpdatePtrans		Compute endogenous state-to-state transition \(P^\star(\theta'|\theta)\) for the current state \(\theta\).
UseEps		Return TRUE if Utility depends on exogenous vector at this state.
Utility	virtual	Default U() ≡ 0.

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 EndogTrans

Public methods
EndogTrans		Task to construct \(\theta\) transition, the endogenous state vector.
Run		The inner work at \(\theta\) when computing transition probabilities.
Transitions		Update dynamically changing components of the program at the time chosen by the user.

 ExPostSmoothing : Bellman : DP

Public fields
Method	static	The smoothing method to use.
rho	static	Smoothing parameter \(\rho\) (logit or normal method)
Public methods
CreateSpaces	static	Set up the ex-post smoothing state space.
Initialize	static	Initialize an ex post smoothing model.
Logistic		Extreme Value Ex Post Choice Probability Smoothing.
SetSmoothing	static	Set the smoothing method (kernel) and parameter.

Inherited methods from Bellman:

ActVal, AutoAuxiliaryValues, Bellman, Delete, ExogExpectedV, FeasibleActions, GetPandV, IgnoreExogenous, InSS, KernelCCP, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, thetaEMax, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps, Utility

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 ExtremeValue : Bellman : DP

\(\zeta\): vector of IID errors for each feasible \(\alpha\)

$$F(z_\alpha) = e^{ -e^{-z_\alpha/\rho} }$$

$$\eqalign{ v(\alpha ; \epsilon,\eta,\theta) &= \exp\{ \rho( U + \delta \sum_{\theta^\prime} P(\theta^\prime;\alpha,\eta,\theta) EV(\theta^\prime) ) \}\cr V(\epsilon,\eta,\theta) &= \log \left(\sum_{\alpha} v(\alpha ; \epsilon,\eta,\theta) \right)\cr EV(\theta) &= \sum_{\epsilon,\eta} V(\epsilon,\eta)P(\epsilon)P(\eta) \cr }$$

Ρ*(α;ε,η,γ) =

Public fields
hib	static const
HMQ	static	Hotz-Miller estimation task.
lowb	static const
rh	static	current value of rho .
rho	static	Choice prob smoothing ρ.
Public methods
CreateSpaces	static	calls the Bellman version, no special code.
Initialize	static	Initialize DP with extreme-value smoothing.
KernelCCP	virtual
SetRho	static	Set the smoothing parameter \(\rho\).
Smooth	virtual	Extreme Value Ex Ante Choice Probability Smoothing.
thetaEMax	virtual	Iterate on Bellman's equation at θ using Rust-styled additive extreme value errors.

Inherited methods from Bellman:

ActVal, AutoAuxiliaryValues, Bellman, Delete, ExogExpectedV, FeasibleActions, GetPandV, IgnoreExogenous, InSS, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps, Utility

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 KeepZ : OneDimensionalChoice : ExPostSmoothing : Bellman : DP

A discrete approximation to \(\zeta\) enters the state vector if the decision is to accept (d>0).

Public fields
keptz	static	Discrete state variable of kept ζ.
myios	static
Public methods
CreateSpaces	static	Create spaces for a KeepZ model.
DynamicTransit	virtual
Initialize	static	Initialize a KeepZ model.
SetKeep	static	Set the dynamically kept continuous state variable.

Inherited methods from OneDimensionalChoice:

AutoAuxiliaryValues, Continuous, EUtility, Getz, HasChoice, Setz, Smooth, SysSolve, Utility, Uz

Inherited methods from ExPostSmoothing:

Logistic, SetSmoothing

Inherited methods from Bellman:

Bellman, Delete, ExogExpectedV, FeasibleActions, GetPandV, IgnoreExogenous, InSS, KernelCCP, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from OneDimensionalChoice:

d, EUstar, pstar, solvez, zstar

Inherited fields from ExPostSmoothing:

Method, rho

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 McFadden : ExtremeValue : Bellman : DP

This is the base class for a static discrete model with extreme value shocks added to the value of actions.

Public fields
d	static	The decision variable.
Public methods
ActVal
CreateSpaces	static	Create state space for McFadden models.
Initialize	static	Initialize a McFadden model (one-shot, one-dimensional choice, extreme value additive error with ρ=1.0).

Inherited methods from ExtremeValue:

KernelCCP, SetRho, Smooth, thetaEMax

Inherited methods from Bellman:

AutoAuxiliaryValues, Bellman, Delete, ExogExpectedV, FeasibleActions, GetPandV, IgnoreExogenous, InSS, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps, Utility

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from ExtremeValue:

hib, HMQ, lowb, rh, rho

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 NIID : Normal : Bellman : DP

See also:

SetIntegration

Public fields
GQLevel	static
GQNODES	static
MM	static
Public methods
CreateSpaces	static	Create spaces and set up quadrature for integration over the IID normal errors.
ExogExpectedV		Complete \(v(\alpha;\cdots,\eta,\theta)\) by integrating over IID normal additive value shocks.
Initialize	static	Initialize a normal Gauss-Hermite integration over independent choice-specific errors.
SetIntegration	static	Initialize a normal Gauss-Hermite integration over independent choice-specific errors.
UpdateChol	static	Update vector of standard deviations for normal components.

Inherited methods from Bellman:

AutoAuxiliaryValues, Bellman, Delete, FeasibleActions, GetPandV, IgnoreExogenous, InSS, KernelCCP, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps, Utility

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from Normal:

AChol, Chol

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 NnotIID : Normal : Bellman : DP

See also:

SetIntegration

Public fields
BigSigma	static	Current variance matrix.
ghk	static	array of GHK objects
R	static	replications for GHK
Public methods
CreateSpaces	static	Create spaces and set up GHK integration over non-iid errors.
ExogExpectedV		Use GHK to integrate over correlated value shocks.
Initialize	static	Initialize GHK correlated normal solution.
SetIntegration	static	Initialize the integration parameters.
UpdateChol	static	Update the Cholesky matrix for the correlated value shocks.

Inherited methods from Bellman:

AutoAuxiliaryValues, Bellman, Delete, FeasibleActions, GetPandV, IgnoreExogenous, InSS, KernelCCP, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps, Utility

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from Normal:

AChol, Chol

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 Normal : Bellman : DP

\(\zeta\): vector of normal shocks

Note: a user should base MyModel on either NIID or NnotIID which are derived from this base.

Public fields
AChol	static	User-supplied Choleski.
Chol	static	Current Choleski matrix for shocks (over all feasible actions)
Public methods
ActVal	virtual	Compute \(v(\alpha;\theta)\) for all values of \(\epsilon\) and \(\eta\).
CreateSpaces	static	Calls the Bellman version and initialize Chol.
Initialize	static	Initialize the normal-smoothed model.

Inherited methods from Bellman:

AutoAuxiliaryValues, Bellman, Delete, ExogExpectedV, FeasibleActions, GetPandV, IgnoreExogenous, InSS, KernelCCP, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps, Utility

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 OneDimensionalChoice : ExPostSmoothing : Bellman : DP

This is the base class required for models solved by finding cutoffs (reservation values) in a continuous error using the ReservationValues method.

The user's model provides the required information about the distribution of \(\zeta\).

• There is a single action variable and
• There are no exogenous (\(\epsilon\)) or semi-exogenous (\(\eta\)) states added to the model. State variables that would be eligible for inclusion in those vectors need to be placed in \(\theta\).
• The model must exhibit a reservation property in z (i.e. a single-crossing property)
• If the number of options is greater than 2 then the crossing points must be monotonically increasing.
• Formally,
$$\eqalign{ \alpha &= (d)\cr \zeta &= (z)\cr \epsilon &= ()\cr \eta &= ()\cr v(d,\theta) &= U(d,\theta) + \zeta_\alpha\cr}$$

• Uz(z): the utility matrix at a given vector of cut-offs z. Uz(z) should return a d.N × d.N-1 matrix equal to the utility of each value of d=i at ζ=z_j. In the case of a binary choice there is just one cut-off and Uz(z) returns a column vector of the utilities of the two choices at z Internally the difference between adjacent values of d is computed from this matrix.
• EUtility(): an array of size d.N that returns the expected utlity of d=j for values of z in the interval (z*_j-1,z*_j) and the corresponding probabilities Ρ[z &in (z*_j-1,z*_j) ]. EUtility() gets z*star from the data member zstar.

Public fields
d	static	single action variable.
EUstar	static	scratch space for E[U] in z* intervals.
pstar	static	space for current Prob(z) in z* intervals.
solvez		TRUE: solve for z* at this state.
zstar		N::Aind-1 x 1 of reservation value vectors.
Public methods
AutoAuxiliaryValues	virtual
Continuous	virtual	The default indicator whether a continuous choice is made at \(\theta\).
CreateSpaces	static	Create spaces and check that α has only one element.
EUtility	virtual
Getz		Returns z* at the current state \(\theta\).
HasChoice		Dynamically update whether reservation values should be computed at this state.
Initialize	static	Create a one dimensional choice model.
Setz	virtual	Sets z* to z.
Smooth	virtual	Smoothing in 1d models.
SysSolve
Utility	virtual	Default 1-d utility, returns 0.
Uz	virtual

Inherited methods from ExPostSmoothing:

Logistic, SetSmoothing

Inherited methods from Bellman:

Bellman, Delete, ExogExpectedV, FeasibleActions, GetPandV, IgnoreExogenous, InSS, KernelCCP, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from ExPostSmoothing:

Method, rho

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 OneStateModel : ExPostSmoothing : Bellman : DP

A model where there is :

• a single decision
• no value shocks
• no dynamics and no foresight

The user simply supplies a (required) static utility function which is called from the built-in version here.

Public fields
U	static	contains \(U()\) sent by the user's code.
Public methods
Initialize	static	Short-cut for a model with a single state so the user need not (but can) create a Bellman-derived class.
Utility	virtual	Built-in Utility that calls user-supplied function.

Inherited methods from ExPostSmoothing:

CreateSpaces, Logistic, SetSmoothing

Inherited methods from Bellman:

ActVal, AutoAuxiliaryValues, Bellman, Delete, ExogExpectedV, FeasibleActions, GetPandV, IgnoreExogenous, InSS, KernelCCP, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, thetaEMax, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from ExPostSmoothing:

Method, rho

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 Roy : NnotIID : Normal : Bellman : DP

This is a base class for a multi-sector static discrete model with normally correlated shocks.

Public fields
d	static	The sector-decision variable.
Prices	static	Vector-valued prices of sectors.
Public methods
CreateSpaces	static	Call NnotIID.
Initialize	static	Initialize a Roy model: static, one-dimensional choice with correlated normal error.
Utility	virtual	Built-in utility for Roy models.

Inherited methods from NnotIID:

ExogExpectedV, SetIntegration, UpdateChol

Inherited methods from Bellman:

AutoAuxiliaryValues, Bellman, Delete, FeasibleActions, GetPandV, IgnoreExogenous, InSS, KernelCCP, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from NnotIID:

BigSigma, ghk, R

Inherited fields from Normal:

AChol, Chol

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 Rust : ExtremeValue : Bellman : DP

• Infinite horizon Ergodic state transition.
• binary choice.

Public fields
d	static	The binary decision variable.
Public methods
CreateSpaces	static	Currently this just calls the ExtremValue version, no special code.
Initialize	static	Initialize a Rust model (Ergodic, binary choice, extreme value additive error with ρ=1.0).

Inherited methods from ExtremeValue:

KernelCCP, SetRho, Smooth, thetaEMax

Inherited methods from Bellman:

ActVal, AutoAuxiliaryValues, Bellman, Delete, ExogExpectedV, FeasibleActions, GetPandV, IgnoreExogenous, InSS, MedianActVal, MyopicActVal, OnlyFeasible, OutcomesGivenEpsilon, Reachable, SetTheta, StateToStatePrediction, ThetaTransition, ThetaUtility, UpdatePtrans, UseEps, Utility

Inherited methods from DP:

Actions, AuxiliaryOutcomes, DrawFsamp, DrawGroup, DrawOneExogenous, EndogenousStates, ExogenousStates, GetAind, GetPinf, GetPstar, GetTrackTrans, GetUseEps, GroupVariables, Indicators, Interactions, KLaggedAction, KLaggedState, MakeGroups, MultiInteractions, onlyDryRun, RecomputeTrans, SemiExogenousStates, SetClock, SetDelta, Settheta, SetUpdateTime, SetVersion, StorePalpha, SubSampleStates, SyncAct, UpdateDistribution, ValuesCounters

Inherited fields from ExtremeValue:

hib, HMQ, lowb, rh, rho

Inherited fields from Bellman:

Aind, EV, Nxt, pandv, Type

Inherited fields from DP:

Blocks, Chi, ClockType, counter, curREdensity, delta, EOoE, EStoS, ETT, gdist, IOE, L, logf, lognm, MyVersion, NKptrans, NKvindex, NxtExog, parents, S, SS, States, SubVectors, tod, tom, userState, Volume, XUT

 Bellman

 ActVal

Compute \(v(\alpha;\theta)\) for all values of \(\epsilon\) and \(\eta\). Not called by User code directly

 Aind

index into CList, determines \(A(\theta)\).

 AutoAuxiliaryValues

 Bellman

Creator function for a new point in \(\Theta\), initializing the automatic (non-static) members. Not called by User code directly

Parameters:

state	state vector
picked	TRUE: in sub sample of states for full solution. FALSE: will be approximated This is called in CreateSpaces() for each clone of MyModel Determine if the state is terminal Set \(A(\theta)\).

See also:

AddA

 CreateSpaces

Calls the DP version.

User code must call CreateSpaces for the parent class that MyModel is derived from.

It will ultimately call this routine.

 Delete

Delete the current DP model and reset.

Since static variables are used, only one DP model can be stored at one time. The primary use of this routine is to enable testing programs to run different problems. User code would call this only if it will set up a different DP model.

The same model with different solution methods and different parameters can be solved using the same structure.

Delete allows the user to start from scratch with a different model (horizons, actions, and states).

The key output from the model must be saved or used prior to deleting it.

 EV

EV(θ)

 ExogExpectedV

Completes \(v(\alpha;\cdots,\eta,\theta)\) by adding discounted expected value to utilities for a given \(\eta\). Not called by User code directly

The columns that are updated are indexed as elo : ehi. The element of the transition used is \(\eta = \) all[onlysemiexog].

decl et =I::all[onlysemiexog];
pandv[][I::elo : I::ehi] += I::CVdelta*sumr(Nxt[Qrho][et].*N::VV[I::later][Nxt[Qit][et]]);

 FeasibleActions

Default \(A(\theta)\): all actions are feasible at all states, except for terminal states. Not called by User code directly

This is a virtual method. MyModel provides its own to replace it if some actions are infeasible at some states.

Returns:

Mx1 indicator column vector
1=row is feasible at current state
0 otherwise.

Example:

Suppose MyModel has a binary action d for which d=1 is feasible only if t < 10. Otherwise, only actions with d=0 are feasible. The following will impose that restriction on feasible actions:

MyModel::FeasibleActions() {
    return  CV(d)==0 || I::t < 10;
}

Comments:

default is to return a vector of ones, making all actions feasible at all states. This is not called at unreachable or terminal states.

See also:

Alpha, Actions, ActionVariable

 GetPandV

 IgnoreExogenous

Return FALSE: Elements of the exogenous vector are looped over when computing U and EV.

The user can replace this virtual method to skip iterating over the exogenous state vector at different points in the the endogenous state space \(\theta.\)

 Initialize

Base Initialize function.

Parameters:

userState

a Bellman-derived object that represents one point θ in the user's endogenous state space Θ. User code must call the Initialize() of the parent class that MyModel is derived from. That routine will ensure this is called.

 InSS

Return TRUE if full iteration over exogenous values and transitions to be carried out at this point (in subsample).

Returns:

Type ≥ INSUBSAMPLE && Type!=LASTT

 KernelCCP

 MedianActVal

KeaneWolpin: Computes v() and V for out-of-sample states. Not called by User code directly

 MyopicActVal

For Myopic agent or StaticClock or just Initial, v=U and no need to evaluate EV. Not called by User code directly

.

 Nxt

TransStore x η-Array of feasible endogenous state indices and transitions \(P(\theta^\prime;\alpha,\eta,\theta)\).

 OnlyFeasible

Extract and return rows of a matrix that correspond to feasible actions at the current state.

Parameters:

myU	A × m matrix

Returns:

selectifr(myU,Alpha::Sets[Aind])

Example:

A model has four possible actions and constant utility, but not all actions are feasible at each state.

static const decl Uv = <0.1; 0.5; 0.7; -2.5>;
⋮
MyModel::Utility() {
    return OnlyFeasible(Uv);
    }

See also:

FeasibleActions, Sets, Aind

 OutcomesGivenEpsilon

Default / virtual routine. Called when computing predictions. Not called by User code directly

 pandv

\(v(\alpha;\epsilon,\eta,\theta)\) and \(P*()\).

 Reachable

Return TRUE: Default indicator function for whether the current state is reachable from initial conditions or not.

The built-in version returns TRUE. The user can provide a replacement for this virtual method to trim the state space at the point of creating the state space. Many state variables will trim the state space automatically with a non-stationary clock assuming initial values are 0.

 SetTheta

Sets up a single point θ in the state space. This is the default of the virtual routine. It calls the creator for Bellman. The users replacement for this must call this or the parent version.

 Smooth

Default Choice Probabilities: no smoothing. Not called by User code directly

Parameters:

inV

expected value integrating over endogenous and semi-endogenous states. Smooth is called for each point in the state space during value function iteration, but only in the last iteration (deterministic aging or fixed point tolerance has been reached.) It uses EV which should be set to the current value of the current state by thetaEMax()

Comments:

This is virtual, so the user's model can provide a replacement to do tasks at each θ during iteration.

See also:

pandv

 StateToStatePrediction

Compute \(P(\theta^\prime;\theta)\). Not called by User code directly

 thetaEMax

Default Emax operator at \(\theta.\) Not called by User code directly

Derived classes provide a replacement.

Computes

$$\eqalign{ V(\epsilon,\eta,\theta) = \max_{\alpha\in A(\theta)} v(\alpha;\epsilon,\eta,\theta)\cr Emax(\theta) &= \sum_\epsilon \sum_\eta P(\epsilon)P(\eta)V(\epsilon,\eta,\theta).\cr}$$

If setPstar then Ρ*(α) is computed using virtual Smooth()

Comments:

Derived DP problems replace this routine to account for \(\zeta\) or alternatives to Bellman iteration.

 ThetaTransition

Computes the endogneous transition given \(\eta.\) Not called by User code directly

Loops over all state variables to compute \(P(\theta^\prime ; \alpha, \eta )\). For StateBlocks the root of the block is called to compute the joint transition.

Accounts for the (vector) of feasible choices \(A(\theta)\) and the semi-exogenous states in \(\eta\). that can affect transitions of endogenous states but are themselves exogenous.

Stores results in Nxt array of feasible indices of next period states and conforming matrix of probabilities.

See also:

ExogenousTransition

 ThetaUtility

Default to be replaced by user if necessary. This function is called before looping over \(\epsilon\) and \(\eta\). The user can place code in the replacement to avoid dupcliate calculations. This virtual function must be replaced when using KeaneWolpin solution method.

Returns:

NaN so that it won't accidentally because user did not provide a replacement.

 Type

Integer code to classify state (InSubSample,LastT,Terminal). This avoids multiple integer values at each point in the state space. Defined in StateTypes. Set in CreateSpaces() and SubSampleStates()

See also:

MakeTerminal, Last, StateTypes

 UpdatePtrans

Compute endogenous state-to-state transition \(P^\star(\theta'|\theta)\) for the current state \(\theta\). Not called by User code directly

This updates either Ptrans or NKptrans. This is called in PostEMax and only if setPstar is TRUE and the clock is Ergodic or NKstep is true.

If StorePA is also true then Palpha is also updated.

 UseEps

Return TRUE if Utility depends on exogenous vector at this state.

 Utility

Default U() ≡ 0. This is a virtual method. MyModel provides a replacement. This simply returns a vector of 0s of length equal to the number of feasible action vectors $$U(A(\theta)) = \overrightarrow{0}$$

 EndogTrans

 EndogTrans

Task to construct \(\theta\) transition, the endogenous state vector. Not called by User code directly

This task loops over \(\eta\) and \(\theta\) to compute at each \(\theta\)

$$P(\theta^\prime ; \alpha,\eta, \theta)$$ It is stored at each point in \(|theta\) as a matrix transition probabilities.

When this task is run is determined by UpdateTime

Comments:

The endogenous transition must be computed and stored at each point in the endogenous state space Θ.

If a state variable can be placed in \(\epsilon\) instead of \(\eta\) and \(\theta\) it reduces computation and storage signficantly.

See also:

SetUpdateTime

 Run

The inner work at \(\theta\) when computing transition probabilities. Not called by User code directly

1. Do Hooks scheduled for AtThetaTrans
2. Compute and store the endogenous \(P(\theta^\prime;\alpha,\theta)\). by calling ThetaTransition

 Transitions

Update dynamically changing components of the program at the time chosen by the user. Not called by User code directly

Things to do before spanning the \(\eta\) and \(\Theta\) state spaces

1. Call PreUpdate hooks (see Hooks).
2. Loop over all States: call its Update() method and Distribution() of random effects.
3. Loop over actions to update Update() them and set the actual values.
4. Compute the exogenous transitions, \(P(\epsilon^\prime)\) and \(P(\eta^\prime)\).

Then span the \(\eta\) and \(\Theta\) spaces to compute and store endogenous transitions at each point.

See also:

SetUpdateTime, UpdateTimes

 ExPostSmoothing

 CreateSpaces

Set up the ex-post smoothing state space.

Parameters:

Method	the SmoothingMethods, default = NoSmoothing
	rho the smoothing parameter Default value is 1.0.

 Initialize

Initialize an ex post smoothing model.

Parameters:

userState

a Bellman-derived object that represents one point θ in the user's endogenous state space Θ.

 Logistic

Extreme Value Ex Post Choice Probability Smoothing.

Sets pandv equal to $$P^{\star}\left(\alpha;\theta\right) = {e^{\rho(v(\alpha;\theta)-V)}\over {\sum}_{\alpha\in A(\theta)} e^{\rho( v(\alpha;\theta)-V) }}.$$

See also:

RowLogit

 Method

The smoothing method to use.

See also:

SmoothingMethods

 rho

Smoothing parameter \(\rho\) (logit or normal method)

 SetSmoothing

Set the smoothing method (kernel) and parameter.

Parameters:

Method	the SmoothingMethods, default = NoSmoothing
	smparam the smoothing parameter ρ AV compatible object. If it evaluates to less than 0 when called no smoothing occurs.

 ExtremeValue

 CreateSpaces

calls the Bellman version, no special code.

 hib

 HMQ

Hotz-Miller estimation task.

 Initialize

Initialize DP with extreme-value smoothing.

Parameters:

rho	AV compatible, the smoothing parameter ρ. CV(rho) < 0, sets ρ = DBL_MAX_E_EXP (i.e. no smoothing).
userState	a Bellman-derived object that represents one point θ in the user's endogenous state space Θ. With ρ = 0 choice probabilities are completely smoothed. Each feasible choices becomes equally likely.

 KernelCCP

 lowb

 rh

current value of rho .

 rho

Choice prob smoothing ρ.

 SetRho

Set the smoothing parameter \(\rho\).

Parameters:

rho	AV compatible object. If it evaluates to less than 0 when called no smoothing occurs.

 Smooth

Extreme Value Ex Ante Choice Probability Smoothing. Not called by User code directly

 thetaEMax

Iterate on Bellman's equation at θ using Rust-styled additive extreme value errors. Not called by User code directly

 KeepZ

 CreateSpaces

Create spaces for a KeepZ model.

 DynamicTransit

 Initialize

Initialize a KeepZ model.

Parameters:

userState	a Bellman-derived object that represents one point θ in the user's endogenous state space Θ.
d	Binary ActionVariable not already added to the model integer, number of options (action variable created) [default = 2]

 keptz

Discrete state variable of kept ζ.

 myios

 SetKeep

Set the dynamically kept continuous state variable.

Parameters:

N	integer, number of points for approximation
held	object that determines if z is retained.

 McFadden

 ActVal

 CreateSpaces

Create state space for McFadden models.

Calls the ExtremeValue version, no special code.

 d

The decision variable.

 Initialize

Initialize a McFadden model (one-shot, one-dimensional choice, extreme value additive error with ρ=1.0).

Parameters:

Nchoices	integer, number of options.
userState	a Bellman-derived object that represents one point \(\theta\) in the user's endogenous state space Θ.

 NIID

 CreateSpaces

Create spaces and set up quadrature for integration over the IID normal errors.

 ExogExpectedV

Complete \(v(\alpha;\cdots,\eta,\theta)\) by integrating over IID normal additive value shocks.

 GQLevel

 GQNODES

 Initialize

Initialize a normal Gauss-Hermite integration over independent choice-specific errors.

Parameters:

userState

a Bellman-derived object that represents one point θ in the user's endogenous state space Θ.

 MM

 SetIntegration

Initialize a normal Gauss-Hermite integration over independent choice-specific errors.

Parameters:

GQLevel	integer[default=7], depth of Gauss-Hermite integration
StDev	integer [default] set all action standard deviations to \(1/\sqrt{2}\) CV compatible A×1 vector of standard deviations of action-specific errors.

 UpdateChol

Update vector of standard deviations for normal components. Not called by User code directly

AV(Chol) is called for each γ, so σ can include random effects.

 NnotIID

 BigSigma

Current variance matrix.

 CreateSpaces

Create spaces and set up GHK integration over non-iid errors.

 ExogExpectedV

Use GHK to integrate over correlated value shocks. Not called by User code directly

 ghk

array of GHK objects

 Initialize

Initialize GHK correlated normal solution.

Parameters:

userState

a Bellman-derived object that represents one point θ in the user's endogenous state space Θ.

 R

replications for GHK

 SetIntegration

Initialize the integration parameters.

Parameters:

R	integer, number of replications [default=1]
iseed	integer, seed for random numbers [default=0]
AChol	CV compatible vector of lower triangle of Cholesky matrix for full Action vector [default equals lower triangle of I]

 UpdateChol

Update the Cholesky matrix for the correlated value shocks. This routine is added to the preUpdate Hook so it is called after parameters may have changed. Not called by User code directly

 Normal

 AChol

User-supplied Choleski.

 ActVal

Compute \(v(\alpha;\theta)\) for all values of \(\epsilon\) and \(\eta\). Not called by User code directly

 Chol

Current Choleski matrix for shocks (over all feasible actions)

 CreateSpaces

Calls the Bellman version and initialize Chol.

 Initialize

Initialize the normal-smoothed model.

Parameters:

userState

a Bellman-derived object that represents one point θ in the user's endogenous state space Θ.

 OneDimensionalChoice

 AutoAuxiliaryValues

 Continuous

The default indicator whether a continuous choice is made at \(\theta\). The user's model can replace this to return FALSE if ordinary discrete choice (or no choice) occurs at the state.

The user-supplied replacement is called for each \(\theta\) during ReservationValue solving. That means whether a choice is made at \(\theta\) can depend on fixed values.

The answer is stored in solvez.

Returns:

TRUE

 CreateSpaces

Create spaces and check that α has only one element.

Parameters:

Method	SmoothingMethods, default = NoSmoothing
	smparam the smoothing parameter (e.g. ρ or σ) Default value is 1.0.

 d

single action variable.

 EUstar

scratch space for E[U] in z* intervals.

 EUtility

 Getz

Returns z* at the current state \(\theta\).

 HasChoice

Dynamically update whether reservation values should be computed at this state. This allows the option to depend on fixed effects.

 Initialize

Create a one dimensional choice model.

Parameters:

userState	a Bellman-derived object that represents one point θ in the user's endogenous state space Θ.
d	ActionVariable not already added to the model integer, number of options (action variable created) [default = 2]

 pstar

space for current Prob(z) in z* intervals.

 Setz

Sets z* to z. Not called by User code directly This is called when solving for z*.

Parameters:

z.

 Smooth

Smoothing in 1d models. Not called by User code directly

 solvez

TRUE: solve for z* at this state. Otherwise, ordinary discrete choice.

 SysSolve

 Utility

Default 1-d utility, returns 0.

See also:

OneDimensional::EUstar

 Uz

 zstar

N::Aind-1 x 1 of reservation value vectors.

 OneStateModel

 Initialize

Short-cut for a model with a single state so the user need not (but can) create a Bellman-derived class.

Parameters:

BorU	either Bellman-derived object or a static function that simply returns utility.
Method	ex-post choice probability SmoothingMethods [default=NoSmoothing]
…	ActionVariables to add to the model Calls Initialize() with either BorU or new OneStateModel(). Sets the ClockTypes to StaticProgram Sends the optional arguments to Actions() Calls CreateSpaces() By calling both Initialize() and CreateSpaces() this makes it impossible to add any state variables to the model.

 U

contains \(U()\) sent by the user's code.

 Utility

Built-in Utility that calls user-supplied function.

 Roy

 CreateSpaces

Call NnotIID.

 d

The sector-decision variable.

 Initialize

Initialize a Roy model: static, one-dimensional choice with correlated normal error.

Parameters:

NorVLabels	integer [default=2], number of options/sectors array of Labels
P_or_UserState	0 [default] initialize sector prices to 0 CV() compatible vector of prices The first 2 options will use the built in Utility that simply returns CV(p). a Roy-derived object (allowing for custom Utility)

 Prices

Vector-valued prices of sectors.

 Utility

Built-in utility for Roy models.

Returns:

OnlyFeasible(CV(Prices))

 Rust

 CreateSpaces

Currently this just calls the ExtremValue version, no special code.

 d

The binary decision variable.

 Initialize

Initialize a Rust model (Ergodic, binary choice, extreme value additive error with ρ=1.0).

Parameters:

userState

a Bellman-derived object that represents one point θ in the user's endogenous state space Θ.

Comments:

The action variable is created by this function and stored in d The value of the smoothing parameter ρ can be changed.