SEMAINE D'ÉTUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 16.

(2) Macroeconomic quarterly model of UK, 1946-1956.
(KLEIN-BALL-HAZLEWO0OOD-VANDOME, Refs. 347-39).

As applied to a model like (36) for a sector of an economy,
a predictive test of type (75) or (76) is of course of limited relevance
 because the sector is liable to exogenous influences that
may disturb or upset the model and thereby the forecasts. So
much the more relevant is a predictive test of economic models
that comprise the economy of an entire nation, although here
too there are external disturbances on the international plane.
The following figures report briefly an attempt to apply the
JANUS quotient to the abovementioned model for UK 1946-1956.
 The model has not been published in such form as to
give the theoretical values obtained from the model in the
observation range; hence the quotient has only been calculated
for three variables, and is partly based on reading off the
graphs of the residuals. Since the tests refer only to a small
fraction of the model it need not be emphasized that the figures
are only given to illustrate the technical procedure of the predictive
 test (26).

Year
1957
1958
1959

Quart

Janus
nuoti-Industrial


productior

Price index o
‘inal output

tere
abe

)

The various generalizations and adaptations of the jaNUS
quotient focus on iust one aspect of forecasting accuracy. na

(**) My thanks are due to Miss INGRID AGERHOIM and Mr. K. NAzIMUn.
DIN for assistance in the computations

[2] Wold - pag. 47