En model for godstransportens udvikling - DCE - Nationalt Center for ...

100%
90%
80%
70%
60%
50% Vogn Ton 32
40%
30%
20%
10%
0%
Firma Ton 32
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
Haulage transport
0%
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
100%
80%
60%
40%
20%
Ton 32
Haulage transport
Km 32
0%
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
an even better understanding of the many different individual elements
influencing the development of freight transport.
100%
90%
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30%
20%
10%
Vogn Km 32
Firma Km 32
0%
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
100%
80%
60%
40%
20%
Own transport
Ton 32
0%
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
100%
80%
60%
40%
20%
Own transport
Km 32
0%
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
Figure 2 The distribution of the amounts transported, and the traffic performance on the size and the ownership
of the vehicles.
Dynamic effects
The description of the model could give the impression that the linking
coefficients in the model are fixed in value. This is not the case
even though some of the coefficients can be assumed constant. The
development is in most cases linear (or almost linear), and can best be
described using a technological trend, but in some cases it seems obvious
to examine other potential explanations of the observed developments.
The underlying assumption or idea is that an influence on
the coefficients from a set of relative prices can be found, where these
prices are some kind of indications of the level of the costs associated
with the different activities. An example of this is the development in
the average trip length, which is assumed to decrease, when the relative
price on transport rises.
Using econometric analyses it is examined whether such pricecoefficient
relations exist. Intuitive explanations for the different price
influences can be given in most cases. Even so, this is not the primary
reason for the changes in the coefficients. Most often the changes are
an indication of more structural changes over longer periods of time.
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