dyn_ols: ols that allows for variables at time t on RHS

time-shift
Houtan Bastani 2017-10-27 13:07:58 +02:00
parent f07696ea5e
commit b407f50753
1 changed files with 187 additions and 0 deletions

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matlab/dyn_ols.m Normal file
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function dyn_ols(ds, varargin)
% function dyn_ols(ds, varargin)
% Run OLS on chosen model equations; unlike olseqs, allow for time t
% endogenous variables on LHS
%
% INPUTS
% ds [dseries] data
%
% OUTPUTS
% none
%
% SPECIAL REQUIREMENTS
% none
% Copyright (C) 2017 Dynare Team
%
% This file is part of Dynare.
%
% Dynare is free software: you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% (at your option) any later version.
%
% Dynare is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with Dynare. If not, see <http://www.gnu.org/licenses/>.
global M_ oo_
jsonfile = [M_.fname '_original.json'];
if exist(jsonfile, 'file') ~= 2
error('Could not find %s! Please use the json option (See the Dynare invocation section in the reference manual).', jsonfile);
end
%% Get Equation(s)
jsonmodel = loadjson(jsonfile);
jsonmodel = jsonmodel.model;
[lhs, rhs, lineno] = getEquationsByTags(jsonmodel, 'name', varargin{:});
%% Estimation
regexpr1 = ...
['(diff\(\w+(\(\W?\w+\))?\))\*$' ...
'|' '\((\w+(\(\W?\w+\))?(\W?\w+(\(\W?\w+\))?)*)\)\*$' ...
'|' '(\w+(\(\W?\w+\))?)\*$' ...
];
regexpr2 = ...
['^\*(diff\(\w+(\(\W?\w+\))?\))' ...
'|' '^\*\((\w+(\(\W?\w+\))?(\W?\w+(\(\W?\w+\))?)*)' ...
'|' '^\*(\w+(\(\W?\w+\))?)'
];
M_endo_names_trim = cellfun(@strtrim, num2cell(M_.endo_names(:,:),2), 'Uniform', 0);
regex = ['(?<chb>^|(\-|\(|+|\*|\/|\^))(?<var>' ...
strjoin(M_endo_names_trim, '|') ...
')(?<cha>$|(\)\-|\(|+|\*|\/|\^))'];
for i = 1:length(lhs)
%% Construct regression matrices
rhs_ = strsplit(rhs{i}, {'+','-','*','/','^','log(','exp(','(',')'});
rhs_(cellfun(@(x) all(isstrprop(x, 'digit')), rhs_)) = [];
vnames = setdiff(rhs_, cellstr(M_.param_names));
if ~isempty(regexp(rhs{i}, ...
['(' strjoin(vnames, '\\(\\d+\\)|') '\\(\\d+\\))'], ...
'once'))
error(['dyn_ols: you cannot have leads in equation on line ' ...
lineno{i} ': ' lhs{i} ' = ' rhs{i}]);
end
pnames = intersect(rhs_, cellstr(M_.param_names));
vnames = cell(1, length(pnames));
X = dseries();
for j = 1:length(pnames)
rhs_split = strsplit(rhs{i}, pnames{j});
assert(length(rhs_split) == 2);
if ~isempty(rhs_split{1}) && rhs_split{1}(end) == '*'
tmp = regexp(rhs_split{1}, regexpr1, 'tokens');
elseif ~isempty(rhs_split{2}) && rhs_split{2}(1) == '*'
tmp = regexp(rhs_split{2}, regexpr2, 'tokens');
else
error('dyn_ols: Shouldn''t arrive here');
end
vnames{j} = tmp{1}{:};
Xtmp = getdata(ds, regex, vnames{j});
Xtmp.rename_(vnames{j});
X = [X Xtmp];
end
Y = ds{lhs{i}};
fp = max(Y.firstobservedperiod, X.firstobservedperiod);
lp = min(Y.lastobservedperiod, X.lastobservedperiod);
Y = Y(fp:lp).data;
X = X(fp:lp).data;
%% Estimation
% From LeSage, James P. "Applied Econometrics using MATLAB"
if nargin == 2
if iscell(varargin{1})
tagv = varargin{1}{i};
else
tagv = varargin{1};
end
else
tagv = ['eqlineno' num2str(lineno{i})];
end
[nobs, nvars] = size(X);
oo_.ols.(tagv).dof = nobs - nvars;
% Estimated Parameters
[q, r] = qr(X, 0);
xpxi = (r'*r)\eye(nvars);
oo_.ols.(tagv).beta = r\(q'*Y);
for j = 1:length(pnames)
M_.params(strmatch(pnames{j}, M_.param_names, 'exact')) = oo_.ols.(tagv).beta(j);
end
% Yhat
oo_.ols.(tagv).Yhat = X*oo_.ols.(tagv).beta;
% Residuals
oo_.ols.(tagv).resid = Y - oo_.ols.(tagv).Yhat;
%% Calculate statistics
% Estimate for sigma^2
SS_res = oo_.ols.(tagv).resid'*oo_.ols.(tagv).resid;
oo_.ols.(tagv).s2 = SS_res/oo_.ols.(tagv).dof;
% R^2
ym = Y - mean(Y);
SS_tot = ym'*ym;
oo_.ols.(tagv).R2 = 1 - SS_res/SS_tot;
% Adjusted R^2
oo_.ols.(tagv).adjR2 = oo_.ols.(tagv).R2 - (1 - oo_.ols.(tagv).R2)*nvars/(oo_.ols.(tagv).dof-1);
% Durbin-Watson
ediff = oo_.ols.(tagv).resid(2:nobs) - oo_.ols.(tagv).resid(1:nobs-1);
oo_.ols.(tagv).dw = (ediff'*ediff)/SS_res;
% Standard Error
oo_.ols.(tagv).stderr = sqrt(oo_.ols.(tagv).s2*diag(xpxi));
% T-Stat
oo_.ols.(tagv).tstat = oo_.ols.(tagv).beta./oo_.ols.(tagv).stderr;
%% Print Output
title = sprintf('OLS Estimation of equation `%s`', tagv);
if nargin == 3
title = [title sprintf(' [%s = %s]', 'name', tagv)];
end
preamble = {sprintf('Dependent Variable: %s', lhs{i}), ...
sprintf('No. Independent Variables: %d', nvars), ...
sprintf('Observations: %d', nobs)};
afterward = {sprintf('R^2: %f', oo_.ols.(tagv).R2), ...
sprintf('R^2 Adjusted: %f', oo_.ols.(tagv).adjR2), ...
sprintf('s^2: %f', oo_.ols.(tagv).s2), ...
sprintf('Durbin-Watson: %f', oo_.ols.(tagv).dw)};
dyn_table(title, preamble, afterward, vnames, ...
{'Coefficients','t-statistic','Std. Error'}, 4, ...
[oo_.ols.(tagv).beta oo_.ols.(tagv).tstat oo_.ols.(tagv).stderr]);
end
end
function retval = getdata(ds, regex, ser)
if strncmp(ser, 'diff', 4)
ser = ser(6:end-1);
lagidx = strfind(ser, '(');
if isempty(lagidx)
retval = ds{ser} - ds{ser}(-1);
else
lag = str2double(ser(lagidx+1:strfind(ser, ')')-1));
assert(lag < 0);
ser = ser(1:lagidx-1);
retval = ds{ser}(lag) - ds{ser}(lag-1);
end
else
retval = eval(regexprep(ser, regex, '$<chb>ds.$<var>$<cha>'));
end
end