Eigen Values

Dynare help (legacy posts)
1

Hi all,

I have a mod. file which gives me BK error. Although two of the eigen values reported by dynare =1; they are counted as if they are > 1. Is there a specific meaning as to why these are counted >1 ? Or what does an eigen value which is equal to 1 mean? Normally, I should have as many eigen values >1 as the number of jump variables. However, I am not quite sure about how dynare treat eigen values when they are exactly equal to 1?

I greatly appreciate any help you might offer.
Thanks.

Here is the dynare output :

EIGENVALUES:
Modulus Real Imaginary

  9.241e-017       9.241e-017                0
  2.888e-016       2.888e-016                0
  1.003e-015      -1.003e-015                0
  1.219e-015      -1.219e-015                0
   6.19e-015        6.19e-015                 0
  6.311e-015      -6.311e-015               0
   1.73e-014       -1.73e-014                0
  1.284e-013       1.284e-013               0
  1.181e-006      -1.181e-006               0
      0.2208           0.2208                    0
      0.5292           0.5292                    0
        0.67             0.67                       0
        0.95             0.95                       0
           1                1                          0
           1                1                          0
        1.01             1.01                      0
        1.01             1.01                      0
        1.01             1.01                      0
       1.508            1.508                     0
       1.909            1.909                     0
       4.574            4.574                     0
  8.554e+005      -8.554e+005             0
         Inf             -Inf                         0
         Inf              Inf                         0
         Inf              Inf                         0
         Inf              Inf                         0
         Inf              Inf                         0
         Inf              Inf                         0
         Inf              Inf                         0

There are 15 eigenvalue(s) larger than 1 in modulus
for 14 forward-looking variable(s)

The rank conditions ISN’T verified!

2

Hi, a unitary eigenvalue is treated as a “stable eigenvalue” by the command check (even if it means that you have a unit root in your model). In your case, the first unit eigenvalue is counted as a stable while the second is counted as an unstable eigenvalue. This may be due to a round off problem. Can you post your mod file ?

Best,
Stéphane.

3

Thank you very much Stephane.

Here is the mod. file I am working with, “modifiednewapproach_ ramsey”.

Is there a way to tell which variable(s) or equation(s) are causing this problem? I tried to modify the model but it did not work.

Thanks again.

Best.
modifiednewapproach_ramsey.mod (7.78 KB)

4

Hi there,

I desperately need help with this eigen value problem. I tried to figure out, which variables are associated with eigen values of 1. I remember that I read in dynare manual or forum that the eigen values are given in some order in dr_.eigval. Are they given alphabetized? I was not successful in modifying my model without knowing which variables are causing the problem of more eigen values >1 for less number of jump variables.
I appreciate any suggestion you might offer.
Thanks.