dynare/tests/ecb/backward-models/solow_forecast.mod

96 lines
2.7 KiB
Modula-2

close all
var Efficiency $A$
EfficiencyGrowth $X$
Population $L$
PopulationGrowth $N$
Output $Y$
PhysicalCapitalStock $K$ ;
varexo e_x $\varepsilon_x$
e_n $\varepsilon_n$;
parameters alpha $\alpha$
delta $\delta$
s $s$
rho_x $\rho_x$
rho_n $\rho_n$
EfficiencyGrowth_ss $X^{\star}$
PopulationGrowth_ss $N^{\star}$ ;
alpha = .33;
delta = .02;
s = .20;
rho_x = .90;
rho_n = .95;
EfficiencyGrowth_ss = 1.02;
PopulationGrowth_ss = 1.02;
model;
Efficiency = EfficiencyGrowth*Efficiency(-1);
EfficiencyGrowth/EfficiencyGrowth_ss = (EfficiencyGrowth(-1)/EfficiencyGrowth_ss)^(rho_x)*exp(e_x);
Population = PopulationGrowth*Population(-1);
PopulationGrowth/PopulationGrowth_ss = (PopulationGrowth(-1)/PopulationGrowth_ss)^(rho_n)*exp(e_n);
Output = PhysicalCapitalStock(-1)^alpha*(Efficiency*Population)^(1-alpha);
PhysicalCapitalStock = (1-delta)*PhysicalCapitalStock(-1) + s*Output;
end;
shocks;
var e_x = 0.005;
var e_n = 0.001;
end;
// Set initial condition for the forecast (we simulate a sample, forecast will start at the end of the sample)
histval;
Efficiency(0) = 1;
EfficiencyGrowth(0) = .5;
Population(0) = 1;
PopulationGrowth(0) = .5;
PhysicalCapitalStock(0) = 1;
end;
[simulation__, errorflag] = simul_backward_nonlinear_model([], 10, options_, M_, oo_);
initialcondition = dseries(simulation__.data(10,1:M_.endo_nbr), 2017Q1, M_.endo_names);
/* REMARKS
**
** dseries object initialcondition may have more variable than required.
*/
// Define the variables for which we want to compute the IRFs
listofvariables = {'Efficiency', 'Output'};
/* REMARKS
**
** If possible do not forecasts all the endogenous variables (this is the default).
*/
// Compute the forecasts
forecasts = backward_model_forecast(initialcondition, listofvariables, 16, true);
/* REMARKS
**
** - The third argument is the number of periods for the forecast. Default is 8.
** - The last argument is for computing (or not) the confidence bands. If false (default), only point forecast is produced.
** - forecasts is a structure, each field is a dseries object for the point forecast (ie forecasts without innovations in the future),
** the mean forecast, the median forecast, the standard deviation of the predictive distribution and the lower/upper bounds of the
** interval containing 95% of the predictive distribution.
*/
// Plot forecast for output
plot(forecasts.meanforecast.Output, '-k', 'linewidth', 2)
hold on
plot(forecasts.lb.Output,'-r')
plot(forecasts.ub.Output,'-r')
hold off
/* REMARKS
**
** In this model there is no steady state (only a stable balanced growth paths), this explains the
** shape of the forecast for Output.
*/