which finally gives
0 |
0— |
0 |
0 | |
+ |
00 |
0 |
0 | |
J= |
0 |
00 |
0 |
+. |
0 |
+0 |
0 |
0 | |
0 |
00 |
+ |
0 | |
This matrix is easily shown to exhibit a |
negative determinant which proves the propo- |
sition, also for all values of γr = γω which are chosen sufficiently small.
Proposition 2:
Assume in addition that the parameters βw2 ,βp2 ,αω,γω and βπm are all set
equal to zero which decouples the dynamics of V c,Vl ,r from the rest of the
system. Assume furthermore that the partial derivative of the first law of
motion depends negatively on V c , i.e., the dynamic multiplier process, char-
acterized by αVc , dominates this law of motion with respect to the impact of
V c.6 Then: The interior steady state of the implied 3D dynamical system
^ - .- — -. .. .. .. ..
V = -αv c ( V — V) — αr (( r — p) — ( Го — π)) (6)
V l = βvι( Vc — Vc ) (7)
Г = —Yr ( r — Го ) + Yp ( p> — ∏) + YV c ( Vc — Vc ) (8)
is locally asymptotically stable if the interest rate smoothing parameter γr and
the employment adjustment parameter βVl are chosen sufficiently small.
Sketch of proof: In the considered situation we have for the Jacobian of these reduced
dynamics at the steady state:
J=
The determinant of this Jacobian is obviously negative if the parameter Yr is chosen
sufficiently small. Similarly, the sum of the minors of order 2: a2 , will be positive if βVl
is chosen sufficiently small. The validity of the full set of Routh-Hurwitz conditions then
easily follows, since trace J = —a1 is obviously negative and since det J is part of the
expressions that characterize the product a 1 a2. ■
Proposition 3:
Assume now that the parameter αω is negative, but chosen sufficiently small,
while the error correction parameters βw2 ,βp2 are still kept at zero (as is the
6i.e., αVc > αpκκpβw .
13