David F. Hendry 53
1940 1960 1980 2000
–0.10
–0.05
0.00
0.05
0.10 Δ^ef
Δef
1940 1960 1980 2000
–2
–1
0
1
residuals forecast errors
1990 1995 2000
–0.025
0.000
0.025
0.050
~Δe
f
Δef
–3 –2 –1 0 1 2 3
0.2
0.4
0.6
residuals
N(0,1)
Figure 1.10 Old model revised data fitted and actual values, residuals and forecasts foref,t
Next, automatic remodeling at 1% on the revised data up to 1989 (with impulse
saturation to remove the outliers) led to:
c 1 =ef+8.49−0.35e+0.21(pf−p), (1.45)
with a much simpler final equation being selected:
ef,t= 0.35
(0.032)
st− 0.25
(0.02)
c1,t− 1 + 0.65
(0.05)
et− 0.29
(0.04)
(pf−p)t
− 0.05
(0.01)
I 30 − 0.08
(0.01)
I 31 − 0.08
(0.01)
I 32 + 0.03
(0.01)
I 70
(
R∗
) 2
=0.90FM(8, 51)=60.4∗∗̂σ=0.012Far(2, 50)=0.65
χ^2 ( 2 )=2.09Farch(1, 50)=0.13Freset(1, 51)=0.11
Fhet(18, 33)=0.89FChow(11, 52)=0.68( 1990 − 2000 ). (1.46)
Nevertheless, despite the revisions, the model in (1.46) has many features in com-
mon with both its predecessors, and is constant over the next 11 years as Figure
1.11 reports, andFChow(11, 52)confirms. The short-run elasticities still exceed their
long-run counterparts, but by less than previously.