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Clean up steady state file examples/NK_baseline_steadystate.m to make it Dynare 4 compatible. 

Also shows how to use file to impose restrictions using the check indicator
time-shift
Johannes Pfeifer 2013-12-03 11:24:01 +01:00
parent 7ada720e7b
commit 1b5641575f
2 changed files with 47 additions and 29 deletions
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9
examples/NK_baseline.mod
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@ -15,7 +15,14 @@
* equations. Moreover, it makes use of a steady state file to i) set
* parameters that depend on other parameters that are potentially estimated
* and ii) solve a nonlinear equation using a numerical solver to find the steady
* state of labor.
* state of labor. It provides an example on how the steady state file can be used
* to circumvent some of the limitation of Dynare mod-file by accessing an external
* file that allows calling general Matlab routines. These capacities will mostly be
* interesting for power users. If one just wants to provide analytical steady state
* values and update parameters, the steady_state_model-block allows an easy and convenient
* alternative. It even allows calling numerical solvers like fsolve. For an example, see
* example3.mod
*
* The model is written in the beginning of period stock notation. To make the model
* conform with Dynare's end of period stock notation, we use the
* predetermined_variables-command.

67
examples/NK_baseline_steadystate.m
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@ -1,14 +1,27 @@
function [ys,check] = NK_baseline_steadystate(ys,exe)
global M_ lgy_
function [ys,check] = NK_baseline_steadystate(ys,exo)
% function [ys,check] = NK_baseline_steadystate(ys,exo)
% computes the steady state for the NK_baseline.mod and uses a numerical
% solver to do so
% Inputs:
% - ys [vector] vector of initial values for the steady state of
% the endogenous variables
% - exo [vector] vector of values for the exogenous variables
%
% Output:
% - ys [vector] vector of steady state values fpr the the endogenous variables
% - check [scalar] set to 0 if steady state computation worked and to
% 1 of not (allows to impos restriction on parameters)
if isfield(M_,'param_nbr') == 1
global M_
% read out parameters to access them with their name
NumberOfParameters = M_.param_nbr;
for i = 1:NumberOfParameters
paramname = deblank(M_.param_names(i,:));
eval([ paramname ' = M_.params(' int2str(i) ');']);
for ii = 1:NumberOfParameters
paramname = deblank(M_.param_names(ii,:));
eval([ paramname ' = M_.params(' int2str(ii) ');']);
end
% initialize indicator
check = 0;
end
%% Enter model equations here
@ -32,6 +45,11 @@ Lambdax=mu_z;
%set the parameter gammma1
gammma1=mu_z*mu_I/betta-(1-delta);
if gammma1<0 % parameter violates restriction; Preventing this cannot be implemented via prior restriction as it is a composite of different parameters and the valid prior region has unknown form
check=1; %set failure indicator
return; %return without updating steady states
end
r=1*gammma1;
R=1+(PI*mu_z/betta-1);
@ -49,9 +67,17 @@ vp=(1-thetap)/(1-thetap*PI^((1-chi)*epsilon))*PIstar^(-epsilon);
vw=(1-thetaw)/(1-thetaw*PI^((1-chiw)*eta)*mu_z^eta)*PIstarw^(-eta);
tempvaromega=alppha/(1-alppha)*w/r*mu_z*mu_I;
ld=fsolve(@(ld)(1-betta*thetaw*mu_z^(eta-1)*PI^(-(1-chiw)*(1-eta)))/(1-betta*thetaw*mu_z^(eta*(1+gammma))*PI^(eta*(1-chiw)*(1+gammma)))...
[ld,fval,exitflag]=fsolve(@(ld)(1-betta*thetaw*mu_z^(eta-1)*PI^(-(1-chiw)*(1-eta)))/(1-betta*thetaw*mu_z^(eta*(1+gammma))*PI^(eta*(1-chiw)*(1+gammma)))...
-(eta-1)/eta*wstar/(varpsi*PIstarw^(-eta*gammma)*ld^gammma)*((1-h*mu_z^(-1))^(-1)-betta*h*(mu_z-h)^(-1))*...
((mu_A*mu_z^(-1)*vp^(-1)*tempvaromega^alppha-tempvaromega*(1-(1-delta)*(mu_z*mu_I)^(-1)))*ld-vp^(-1)*Phi)^(-1),0.25,options);
if exitflag <1
%indicate the SS computation was not sucessful; this would also be detected by Dynare
%setting the indicator here shows how to use this functionality to
%filter out parameter draws
check=1; %set failure indicator
return; %return without updating steady states
end
l=vw*ld;
k=tempvaromega*ld;
@ -68,27 +94,12 @@ g2=epsilon/(epsilon-1)*g1;
%% end own model equations
for iter = 1:length(M_.params)
for iter = 1:length(M_.params) %update parameters set in the file
eval([ 'M_.params(' num2str(iter) ') = ' M_.param_names(iter,:) ';' ])
end
if isfield(M_,'param_nbr') == 1
if isfield(M_,'orig_endo_nbr') == 1
NumberOfEndogenousVariables = M_.orig_endo_nbr;
else
NumberOfEndogenousVariables = M_.endo_nbr;
end
ys = zeros(NumberOfEndogenousVariables,1);
for i = 1:NumberOfEndogenousVariables
varname = deblank(M_.endo_names(i,:));
eval(['ys(' int2str(i) ') = ' varname ';']);
end
else
ys=zeros(length(lgy_),1);
for i = 1:length(lgy_)
ys(i) = eval(lgy_(i,:));
end
check = 0;
NumberOfEndogenousVariables = M_.orig_endo_nbr; %auxiliary variables are set automatically
for ii = 1:NumberOfEndogenousVariables
varname = deblank(M_.endo_names(ii,:));
eval(['ys(' int2str(ii) ') = ' varname ';']);
end