From 1098fb4571cd66c9641b53bded9ad865acc08c40 Mon Sep 17 00:00:00 2001
From: Michel Juillard <michel.juillard@ens.fr>
Date: Tue, 1 Jun 2010 20:36:48 +0200
Subject: [PATCH] ramsey_policy: eliminating unnecessary leads and lags

---
 matlab/dyn_ramsey_dynamic_.m | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/matlab/dyn_ramsey_dynamic_.m b/matlab/dyn_ramsey_dynamic_.m
index ac27b0e6a..3b44f9495 100644
--- a/matlab/dyn_ramsey_dynamic_.m
+++ b/matlab/dyn_ramsey_dynamic_.m
@@ -223,6 +223,17 @@ i_leadlag1 = zeros(size(i_leadlag1))';
 i_leadlag1(nonzeros(m)) = 1:nnz(m);
 i_leadlag1 = i_leadlag1';
 
+%eliminating lags in t-2 and leads in t+2, if possible
+if all(i_leadlag1(5,:)==0)
+    i_leadlag1 = i_leadlag1(1:4,:);
+    max_lead1 = 1;
+end
+
+if all(i_leadlag1(1,:)==0)
+    i_leadlag1 = i_leadlag1(2:4,:);
+    max_lag1 = 1;
+end
+
 % setting expanded model parameters
 % storing original values
 M_.endo_nbr = endo_nbr1;